The Good: The Roku 4 delivers 4K video, promising the best-quality video streams available today. It has more 4K-capable apps than other devices and makes 4K TV shows and movies easy to find. The remote has voice search, a unique headphone jack for private listening, and a finder function in case it goes missing in the couch cushions. Roku's platform is the best, with the most apps, comprehensive search results arranged by price, and a simple interface that doesn't favor one service over others. The Bad: Other devices like Apple TV and Amazon Fire TV offer more capable voice interactions beyond keyword search, and more robust gaming. Most 4K TVs have similar 4K apps already built-in, 4K content is still scarce, new 4K movies are expensive, and image quality with 4K streaming isn't a big improvement over standard HD streams. If you don't want 4K, other Rokus are a better value. The Bottom Line: The Roku 4 is the best way to get the most 4K video today, but isn't worth the extra money for most buyers. When you drop a chunk of change on a shiny new thing, like a big TV with 4K resolution, the urge to accessorize can be overwhelming. If that urge has just overtaken you, the Roku 4 looks pretty sweet.This squat little box spits out the widest variety of 4K video available today -- including Netflix, YouTube, Amazon, Vudu and M-Go -- and makes finding actual 4K TV shows and movies easier than ever. , and newer 4K movies cost a bundle, but if you're hot to demo that new TV, I guess some 4K is better than no 4K.Streaming videos in 4K resolution can deliver better picture quality than HD or 1080p resolution streams, but you'll need a big 4K TV, a fast Internet connection, and in the case of Netflix, the most-expensive subscription plan to take full advantage. . Even to an image quality stickler like me the best non-4K streams from Netflix and Amazon look pretty awesome, and in my comparisons I find it difficult to tell the difference between them and actual 4K streams.Compared with most 4K TVs, the $130 price of the Roku 4 is chump change, but in the puck-infested world of media streamers it's pretty expensive. And if you're on a budget, it's largely unnecessary. That's because your 4K TV probably already has access to Netflix and Amazon's 4K stuff, and maybe YouTube or others as well. And in the case of , which (wait for it...) promises even better quality than regular old 4K, those apps might even be more capable than Roku's. In most other ways, of course, Roku and other external streamers .Roku 4's competition includes the and , both of which also handle 4K, but both ultimately fall short. Then there's , which could offer enough useful capabilities to unseat Roku 4 as the best high-end streamer, even though it doesn't have 4K (or an Amazon video app). I'll know more once I review it. In the meantime maybe you know you like Roku better anyway, or you just want the best 4K video device available today. That's the Roku 4.The box: A pancake packed with ports, processingThe Roku 4 looks like someone ran over a with a pickup truck. The new "box" is a thick, squared-off black plastic pancake, wider and deeper than other streamers but squat overall. Externally it's basically the opposite of the taller, chunkier new Apple TV.The top is matte black and the sides glossy, slightly taller along the edges than the middle. Adornments include the big "4" up top, the trademark purple fabric Roku tag, and the discrete "Roku 4" logo on the front. The bottom is nicely rubberized to minimize slideage.Mounted topside you'll also find the lone button, shaped like a miniature version of the Roku remote. That's appropriate because it's used to operate the remote locator function.Roku omitted no connection. On the side there's a USB port, and around back you get the best selection of ports on any streamer available today outside the Nvidia Shield: HDMI, Ethernet, optical digital audio and a MicroSD card slot. Most other new streamers drop optical digital audio, which is the easiest way to get 5.1 channel surround to older devices that lack HDMI. And Roku has more 5.1-capable apps than anyone.The USB port can connect to USB sticks and hard drives for playback of photo, music and video files using the Roku Media Player app (see below for testing). The MicroSD card port can take cards up to 64GB if you find the need to expand the Roku 4's storage. Like on the Fire TV, this feature is only useful for gamers (the SD card can't be access for media file playback), and of course Roku has very few games compared to Fire TV and Android TV.One advantage over streaming sticks is the presence of an Ethernet port, and in many locations Ethernet will provide a more reliable, higher-bandwidth stream than Wi-Fi (something that's especially important for 4K streaming, which generally needs a hefty 15Mbps connection). Of course, Roku 4 supports the latest 802.11ac Wi-Fi standard, too, and it worked flawlessly in our test lab.Roku also mentions a quad-core processor for faster response times. In my tests menu navigation and other tasks didn't seem to go noticeably faster than the already very zippy Roku 2 or 3, however, and apps like Netflix and YouTube didn't launch any faster. The same goes for other newer streaming boxes: all are plenty speedy for most users.The cure for RLS (remote loss syndrome)The biggest improvement on the Roku 4 remote is its cool finder function. Press the button on the top of the box and the remote emits an alarm sound -- your choice of whistle, submarine-style sonar or "Ride of the Valkyries," among others -- from wherever it happens to be hiding. It's a great feature for people who always misplace the clicker, provided you're using the actual Roku remote instead of a universal model. Now if only Roku would sell a tiny accessory speaker I could paste to my .Otherwise the remote is identical to that of the Roku 3. It's chunkier and looks a bit dated next to the , (even the old one) and remotes, but still feels natural in the hand.Like most streaming media device clickers, and unlike the more basic remote found on the , it uses uses Wi-Fi Direct so it doesn't require line-of-sight to operate. You can stash your Roku 4 pretty much anywhere in your system, and point the remote anywhere, and it works fine.The "return" button on previous Roku remotes -- not to be confused with the much more useful "back" button -- has been replaced by a little magnifying glass that summons the voice search dialog. Otherwise the buttons are basically the same.Roku kept the A\/B keys for gaming, and the volume controls to the side effect the headphone output only. I like the ability to instantly launch Netflix and Amazon, but I found the buttons for services to which I didn't subscribe (namely, Rdio) irksome and a rare departure from Roku's content-agnostic ethos. Another annoyance is the main OK key's unconventional placement better below the four-way cursor, rather than in its midst.The Roku way to play 4K, eh?Unless you lose your remote all the time, the main reason to spend the extra money on a Roku 4 over cheaper models is to get 4K capability. As with all external streamers, you'll need to connect it to an input on your 4K TV to enable 4K playback with most copy-protected content, which includes just about everything available to stream today.True to form, Roku offers the most apps of any streamer with 4K. At launch its apps for Netflix, YouTube, Amazon, Vudu (which ), M-Go and ToonGoggles all support 4K streaming, and PLEX and the Roku Media Player app both handle local playback of 4K files. The only 4K streaming app I know about that Roku 4 doesn't currently support is UltraFlix, found on Vizio and some other 4K TVs. It offers a hodgepodge of mostly older movies and other video. Roku's rep told me they're working to add UltraFlix as well, but couldn't tell me when.Meanwhile Amazon Fire TV only offers 4K from Netflix and Amazon, although it says YouTube and PLEX will be added soon. Nvidia Shield has Netflix, YouTube, PLEX and numerous video player apps including VLC Player and MX Player, but it doesn't have an Amazon Video app at all. Advantage Roku, right? Not so fast. If you have a 4K TV, chances are it already has a built-in app or three that offers 4K streaming or even downloads. That app may even support for HDR video. HDR promises even better image quality than 4K, with brighter highlights and expanded color. , and offers a handful of HDR shows and movies. Vudu and Netflix will follow suit with their own HDR content later this year.Right now no external device supports HDR, including Roku 4 (like Nvidia, Roku claims it might add such support in the future, but Amazon's Fire TV, ironically, will not). The vast majority of 4K content, of course, isn't in HDR, and of course no Smart TV system is as good as Roku's in terms of update frequency, customization and ease of use. And of course some don't support every 4K app Roku does; Vizio's M series, for example, still doesn't deliver 4K YouTube.Roku makes 4K content easier to find than any other platform. The app store (Roku calls it a Channel Store) has a dedicated section called "4K UHD Content Available" that collects all of the apps that deliver 4K.Even better, there's a dedicated Roku channel called "4K Spotlight." It's designed to showcase individual 4K movies, TV shows and videos. I was surprised to see a relatively solid selection at press time: 133 movies, 44 TV shows and 33 videos were listed. Selecting one takes you to the app to play it back. Most of the movies are from M-Go, Amazon and Vudu, and while a few are free (for Amazon Prime members), most cost plenty to rent (if available, it's typically $10) or buy ($20 to $30). All of the TV shows are original series from Amazon (free for Prime members) or cartoons from ToonGoggles (free, with ads). And all of the videos are from YouTube (free).Unfortunately, Netflix's substantial 4K catalog isn't included among the 4K Spotlight offerings. When I asked why, Roku's rep told me "We encourage all of our content partners to participate, but some are still evaluating the opportunity." To watch 4K shows via Netflix, you'll have to hit Netflix's app directly.I'd like to see some ability to sort the 4K offerings by price, genre or release date, and it would be even better if Roku's excellent search offered a "4K only" filter, either from within Spotlight or globally. Those are nitpicks though, and likely coming in the future as more 4K content rolls out. So how does 4K look? As I've seen in previous viewing tests, it provided very little improvement in my experience over the best 1080p streams. I used the , a high-end 75-inch TV, to judge image quality between the non-4K Roku 3 box and Roku 4. Switching quickly between the two boxes watching "Narcos" on Netflix from a theatrical seating distance of about eight feet, the two looked basically identical. The pores on Escobar's face as he peers out the plane window, the hills and buildings of Medell\u00edn spread out below, the small letters on the wall or the flag in an office, all looked equally sharp. The same went for "Daredevil." I've seen these same minuscule differences with most 4K material and source devices. The simple fact is that 1080p streams from Netflix, Amazon and others look so good already, that the 4K streaming tier provides little benefit.