Optoma DV10 DLP Projector

I've wanted a projector for a long time and I've recently been researching them. The main reason I want one is to watch movies, play Xbox 360, and of course the occasional sporting event. The Optoma DV10 is the one of choice right now. The only thing I'm worried about is how the Xbox games will look like on it. It says it supports 720p sources, but the resolution isn't that high. Will there be a considerable difference in visual quality from say a 20" LCD monitor? Thanks in advance.