I have the GT750 which is the newer model of this projector. Not sure about all of the specs, but I believe the main difference is the fact that the 750 does 3D natively, where as this needs an expensive converter box to utilize 3D. Worth paying the little extra for the 750 if 3D is your thing.
As for the fact that it is 720p, I think most people get bent out of shape over the whole 720 vs. 1080 situation. Truth is, unless one would have them side by side, most people wouldn't be able to tell the difference. Even then, maybe not so. I used to have two samsung LCD tv's, one 720p and the other 1080p, and the 720 had a better picture in my opinion. This is especially true in video games, which these projectors are designed for. I'll take lower res over the extreme lag of most projectors anyday. I have used two different brands of 720p projectors over the past 5 or 6 years, and I have been more than satisfied with the picture quality. That is on screens ranging from 92" to 106". Anyone who has viewed my projectors have always assumed they were 1080 since the picture is that good.
The one caveat with this projector is its main selling point...short throw. Since it is DLP you already start with very minimal range for the throw(just a downfall of DLP vs. LCD). Add in the fact that this model has ZERO zoom capabilities and placement becomes tricky and requires a lot of moving of the projector to get it to fit the screen size. On top of that, the projector has to sit around approx. 10 inches or so from the top or bottom of the screen(depending on if you are placing it on a stand like I do, or ceiling mounting it). Table mounting isn't too bad as moving the projector in small increments to adjust the the image to your screen is a lot easier than hoping you have it mounted exactly as needed to the ceiling. Not much room for error with this one.
All in all, it would be a great toy to use for casual movie watching, game playing, etc.(my main use for it, although it is in use daily for me) As for a serious home theater setup, look elsewhere to a projector that offers more placement flexibility. And as for all projectors, splurge on an inexpensive screen. It makes all the difference in image quality. You can find cheap 16:9 pull down screens for under a hundred bucks. I got one from Tiger direct for under 50!
Good luck to all whom are looking for a projector to purchase.