+1, If you get a 720p HDTV it will look like complete ass as a PC Monitor. A 1080P HDTV looks superb however and I will be gaming on this westy for years and years from now. The different might be hard to see when watching movies or tv. Try to plug a PC into them both and see which one has the better image.
Its because of the resolution.
1080p TVs run at a native resolution much higher than 720p/1080i TVs and with PC work its all about the resolution!