Got my Roku today. My Wife hooked it up to our Onkyo 606 using HDMI, hooked up the ethernet and started playing. She had a movie playing in just a few minutes.
Unit is really small and takes up almost no footprint, so it can easily fit in to any setup. Remote is kind of small for my hands, but I'll try getting it setup on my harmony later.
Picture quality is very good, not DVD good, but better than most SD stuff you are used to. It's really right on par with the SD picture I get from Uverse (which is the best SD I have seen that is non-OTA) I'm not sure if my 606 is improving the video or not a bit, but the quality does seem better than I remember when I had a PC hooked up to the home theater for the watch instantly stuff. (I had an onkyo 604 at that time)
Audio is plain old stereo, but that is all I expected.
Performance on the first movie is exactly like I remember on the PC, we have a 10meg HSI connection, so we didn't run into any lags or pauses etc.
Menus:
To watch movies, you cycle through your instant queue and it shows you the DVD art or theater poster art of the movie. Like shaun-ohio said, you navigate around the categories and genre's, add them to the queue and enjoy. It's really very easy for the novice or the technology challenged.
You can then view the movie information like any netflix movie synopsis and then begin watching the movie.
Took only a few seconds to start the movie buffer and start playing the feature.
FF/REW worked pretty much as one would expect, Still screens were pretty clean, not that I expect to capture screen shots from this service so that is really not a big deal.
One thing missing that I really like with BD/HD-DVD's and even the PC client for netflix is the timeline bar, that is not a feature on this Roku unit, so I would hope that since this is so new, things like that get added. The bar is there if you pause, but not while you are watching the movie.
Had to come back to work but in the 30 minutes or so I have had to play with the Roku box, it seems pretty intuitive. We watched 30 minutes of "Worlds Fastest Indian" and it was perfect in playback (btw, it's a great movie IMO, well worth watching).
My wife is already excited that while coupling this with our Netflix discs, our VOD from ATT Uverse, and the nice selection of kid friendly stuff on netflix instant view that we'll always have something new to watch with the kids and we'll also watch movies that we will probably find teriffic (there are some gems on netflix watch instantly) movies that we otherwise would not have wasted a DVD rental on.
Also, the box doesn't seem to heat up in the time we played with it. Not that I really expect it to.