I believe this post in order that they think that would be better 360 or PC: (nowadays I have both possibilities)
360:
- It was never slowing down
but will be running at low settings, set your pc to them and you'll be beating it - Big screen
connect up your pc with a controller if you need to, but monitors actually appear bigger to the user than large tv's from 2-3m away - High definition
1280x720, achievable in pc games since 2000(and probably before) PC:
- Better graphs
- Editor (I read It in another post)
woo! - Mods
- Free Online
Before saying nothing that the Crysis me works in this PC with the graphs to the maximum and does not slow down
PC:
ATI Radeon 3600 Series 512 MB
(I will buy the better one, because this one belongs to my old PC)
even if you didn't, it's a no brainer to get it on pc, you'll run it better than the xbox with this card Ram 4 gb
Some edits for quick answers

But essentially the xbox has no advantage over the PC version with your pc, even if it the gpu is quite old. You'll be able to easily match xbox 360 graphics at better framerates.