I ran my XBOX 360 with a Optoma H30 for a while, similar sort of spec to the H27 although different DLP chip but I have to say I wasn't disappointed with the picture. It was much better than what I was expecting.
However after hooking the 360 to a mates Sanyo Z3 the extra resolution did make a worthwhile difference but maybe not quite as much as I was expecting.
If you can afford the extra outlay a native 720P projector is better but once lost in the action on a big screen, the truth is you probably won't notice that much difference.
hi i dont have a 360 but i do have a h27 with sky hd running through componant and the picture is very nice you would not be disapointed
i know it should not be but when i compare standard sky to hd the picture is better even on a none hd dlp chip
i am a very happey h27a owner but i will upgrade to a hd projector in a few years time