It feels pretty great imo. The quality isn't as good as on CRT tv set but the size (hello Freud) makes it even overall. I'm actually playing much more since I've got my projector than when I used to play on TV and, something unexpected, many friends come for multiplayers sessions. It never happened before, even if it has nothing to do with the qualiti itself. :]
The main problem at the moment is the darkness, I don't mean the light in the room but the colors displayed. Games like Splinter Cell will suffer. If you're a Nintendo player it will be heaven that's for sure, the 1st time I saw Double Dash running in progressive scan I was in awe (until I tested F-zero, which is the most impressive game I've played on my projector).
Also, be sure to get some decent cables, RCA wont be good enough. I hardly played any PS2 game until I got a YUV cable instead of the normal one.