Ugh, I don't know about your 360 but MY 360 plays modern games like CRAP.
Massive popup, low draw distance, stuttering, low frame rate and HORRIBLE resolution. It's /at least/ 10x crappier than my PC at playing last years games, even games that were written FOR the XBOX!
The 360 is already 1-2 years WAY late for an upgrade

having to sit for 1-2 more is going to be intolerable. Usually I look for xbox versions of most games as I like to play on the bigger screen and more comfortable chair, but I'm not buying any more now, the latest crop, compared to a couple I've played on my PC (With a 2 year old card!) have convinced me that the 360 is just too much crap to waste money on a game that I can get for the PC as well... It was only barely comparable to a PC 6 years ago, playing on it is like being stuck in 2005 permanently