The Good: The TCL S405 series are among the least expensive 4K TVs on the market. Roku TV delivers the simplest, most comprehensive smart TV experience on the market. A superb user interface delivers thousands of apps and the most 4K video of any system. The Bad: Worse picture than competing Vizio TVs. 4K resolution and HDR don't deliver a substantial improvement in image quality. The Bottom Line: Although the image quality is just "good enough," the S405 series is still an excellent choice for budget buyers focused on streaming and simplicity. \tUpdate fall\/winter 2018 The TCL 55S405 is still our favorite budget 55-inch TV recommendation for people who put a higher priority on streaming and convenience than they do on picture quality, and it will likely remain so through early 2019, at least. It may surprise you to learn that, in today's lightning-fast tech world where cool new products appear every day -- especially for the busy holiday buying season -- we're still recommending a product that was introduced in 2017, when this review first published. TCL is still selling the S405 series and never released a 2018 replacement. Since we wrote the original S405 review we've tested a couple of newer models and some stuff has changed. Here's our current buying advice. Versus the less expensive S305 series: If you want a budget smart TV smaller than 55 inches, get this series instead. It ranges from 28 to 49 inches, the picture is "good enough" and the built-in smarts are superb. The only difference between the S305 and S405 is 4K resolution and HDR compatibility, and neither provide enough image quality benefit to be worth the price increase. Versus the more expensive Vizio E series: This TV got a higher overall rating than the S405 and is worth the extra money if you prioritize image quality over built-in smart TV features and convenience. It's also our top budget pick in sizes larger than 55 inches. Versus the more expensive TCL 5 series: Its superior style and feature upgrades (Dolby Vision HDR, a wider color gamut, an enhanced remote) aren't worth the extra money for most people at 55 inches. Since the 65-inch S405 is no longer available, however, the 65S517 is a solid choice if you don't want the Vizio E or can't afford the superb TCL 6 series. The full review as it originally appeared in August 2017 continues below. Although the rating and buying advice here is current, nothing else has been updated. New Roku software additions such as Featured Free and Google Assistant aren't mentioned and the comparisons all refer to older TVs. If you're curious how the 55S405 compares to 2018 models, check out the Vizio E and TCL 5 series reviews linked above. When you're in the market for a budget TV you have to make some compromises. In the case of the TCL S405 series, you'll be sacrificing some picture quality to get the best built-in streaming app system around. Roku TVs like this TCL trounce the built-in app systems on most other TVs. They're ridiculously simple to use, quick and responsive and they receive constant updates of new features and apps. Streaming staples like Netflix, Amazon Video and Sling TV are front-and-center and just a remote shortcut button away: no need to switch inputs to another device. And the S405 can stream more stuff in the highest quality -- 4K and HDR -- than non-Roku smart TVs. Compared with the Vizio D series and E series TVs, however, the S405's actual picture quality doesn't quite measure up. Its 4K resolution and HDR compatibility don't make up for the basics: namely lighter black levels that hurt contrast and deliver less pop than those Vizios. So you have a choice. If you want the best picture for your budget dollar, get a Vizio (and maybe attach a separate Roku box) or spend more for the TCL P series. But I'm betting plenty of people will be perfectly happy with the "good enough" picture and superior streaming and convenience of the S405, especially since it's even cheaper than those 4K Vizios. \tHello-ku, Roku! Fire up the S405 and you won't be greeted with something from an HDMI input, like whatever channel your cable box is tuned to. Instead you'll see a grid of app icons, much like your phone's home screen. A few of those icons indeed lead to HDMI inputs (and you can rename them "cable box," "Xbox" or whatever), but most are apps. I love the system's simplicity and customization, although I wish one-third of the screen weren't occupied by a big ad. Roku TVs have access to all the thousands of apps found on Roku's platform, which still offers better coverage than any competitor, smart TV or otherwise. Netflix, Amazon, YouTube, Hulu, Plex, HBO Now, Showtime, Sling TV, PlayStation Vue, DirecTV Now, Vudu, Google Play Movies and TV, Watch ESPN, Fox Sports Now, FX Now, Comedy Central, Starz, PBS Kids... if there's a video app that isn't iTunes, Roku almost certainly has it. And if that app streams in 4K or HDR, the S405 series can likely deliver those streams, too. One exception is Vudu, however, which isn't available in HDR on this set (yet), just 4K. I especially like the "4K spotlight" app that surfaces individual 4K and HDR TV shows and movies across a few providers, although unfortunately Netflix isn't one of them. I also like the "4K content available" list in the app store, which shows all of the 4K apps available on Roku. All of the Roku TVs I've tested respond quickly and serve up videos with minimal delays. Search is the best in the business overall, and in general the interface is as friendly and simple as it gets. For more info, check out my review of my favorite 4K Roku device, the Roku Premiere+. \tNice extras, but not much of a voice Roku TVs like the S405 also offer a few extras not found on Roku boxes like the Premiere+. One is the ability to pause live TV from an antenna. Another is More Ways to Watch, which suggests streaming alternatives to TV shows and movies from antenna, cable or satellite, and even Blu-ray. One area where Roku falls short, however, is voice control. Samsung, Sony and LG all let you talk into your TV remote to perform searches and in some cases control other gear. Vizio's E series can be controlled by a Google Home, and all of them bow to the king of voice on TV: the Amazon Fire TV Edition with Alexa. On the TCL S405, however, the only nod to voice is being able to search by speaking into your phone using the Roku app. At least the app offers private listening, the cool ability to listen via headphones and mute the TV's speakers -- and to many users that's better than any voice control feature. \tFeatures and connections: Basic 4K The S405 lacks the local dimming that vaults the better Vizios, not to mention TCL's own P series, into "very good" picture quality territory. As a result it also can't deliver HDR content with the same impact. Unlike the P series, the S405 handles only HDR10, not Dolby Vision. The P series also gets a superior remote, which included a headphone jack for private listening, voice search capability and an RF connection, so you don't have to aim it at the TV. The S405's remote is standard, simple Roku fare, with a decent mix of popular cord cutter shortcuts.