The marketing material for the projector says you can project an image up to 120 inches, but we generally stayed in the 42- to 50-inch range and kept the room dark (when using a projector, turning the lights off makes a huge difference in picture quality).
All in all, the picture was satisfactory for casual viewing and significantly better and brighter than what you get from many smaller pico projectors, which simply don't offer the same brightness capabilities. However, because the resolution isn't all that high, the picture was definitely soft compared with what you'd get from even an entry-level 720p LCD TV. (The problem with a projector--especially non-HD ones--is that the larger the image you project, the softer the image gets).
Another caveat: the Neo-i doesn't support 1080p input. However, 480i, 480p, 720p, and 1080i will work just fine. (It's not a big deal for a non-HD projector, but it did cause us some confusion when we first hooked up our Blu-ray player, which had been set at 1080p.)
The Blu-ray image we projected was sharper than the picture from the digital copies we had on our iPhone. But though the difference was noticeable, it wasn't huge. To be clear, when you project a Blu-ray disc with this projector, you are not projecting an HD image. It's more like watching a DVD or perhaps a slight step down, especially as you go bigger with your image.
We didn't expect the world from the built-in speakers and we can't say they sound all that great (most TV speakers will deliver superior sound). But the speakers played loud enough to hear dialogue clearly enough, which is important--and a big step up from the muted sound you get from virtually all pico projectors.
In the end, we came away liking the Neo-i, and appreciated the convenience of the iPod/iPhone dock integrated into the unit, which is a big plus and the future of these types of "portable" projectors.
As for its value, the key question is how you plan on using it. Optoma sees it as an entertainment projector rather than a business projector, and it might have some appeal for dorm room use and trips with the kids to spots where you don't have access to a TV but do have access to power. You could potentially use this as a bedroom or playroom projector, but with LCD TVs coming down in price, you'd get a better picture for the money from a 37- or 40-inch LCD set.
For those trying to choose between this model and Optoma's PK301--which we consider one of the best pico projectors out there right now--that projector is obviously much smaller and is truly a pocket projector. We also like its simple, black design better.
Those pluses aside, the PK301's built-in speakers are really tiny and don't output nearly as much sound as the Neo-i's speakers do. Also, to hook up your iPhone or iPod, you have to attach an optional AV cable, which is kind of pain (the PK301 has a microSD card slot and built-in media software, so it's better to play your content off a memory card).
In the final analysis, the Neo-i clearly delivers a better projection experience than the PK301, but it is more of a full-size projector that doesn't include a battery-powered option right out of the box.
Before buying this, I'd say you really should think about how you might use it. You can connect a computer to it, but it's really designed first and foremost to be used with an iPhone or iPod. It won't replace the picture quality of an LCD TV, but it is an acceptable substitute--at least on a temporary basis.