Couldn't be happier with my H31
I did a lot of research and comparisons before I purchased my Optoma H31 about 4 months ago, and I can't sing its praises loud enough. While its 854 x 480 native resolution won't please a hardcore videophile, an entry-level home theater enthusiast will be more than blown away by the exceptional picture quality and color reproduction. My biggest concern with buying a projector was decent-looking black levels, and I'm thrilled to say that the H31 does an amazing job with "dark" movies like "Batman Begins" and "Aliens." Also, no one who has watched my projector has ever mentioned seeing any rainbow artifacts of any kind. Set-up was quite easy (I did it myself, and I am no home improvement expert, I assure you), and despite some complaints that I have read about calibration issues, I found the image from my H31's factory settings to look spectacular right out of the box, and I have not needed to make any major adjustments. Fan noise is extremely low (I sit almost right beneath it, mounted on an 8-ft. ceiling, and never notice it running, even with volume muted), and the picture looks unbelievable sitting about 15 feet away from my 106-inch Da-Lite widescreen -- no screen door effect at all from that distance and closer. I haven't run HDTV on it, but DVDs in progressive scan through standard component cables look pretty sweet and SDTV looks better than I anticipated.
There are only two things to look out for with the H31. The high throw angle is pretty pronounced, so if you do a ceiling mount your screen might need to be mounted a little lower than you might like (It worked well in my family room, but I can see where it could be problematic for some), and there is no vertical lens shift capabilities. Ambient light control is also important for the H31 (but it is for all projectors, really); in a lit room the image is very much visible, but the image really "pops" in a fully darkened environment.
Overall, the H31 is a tremendous value...especially for those of us who have a little tighter budget. Dollar-for-dollar, you will not be able to get a picture this rich and vibrant with such an impressive screen size at a price any better going any other route. A higher-end projector with greater resolution will outperform the H31, but only the most-trained eyes would notice this without seeing the comparison side-by-side. You cannot go wrong with this projector!
One last note...if you love movies, front projection is the only way to go. The projected image, even when digital, replicates the majesty of the cinematic experience far better than even the highest quality plasma or LCD...in my humble opinion, at least.