This is everything there is to know about my computer:
http://wolframpc.blogspot.ca/2012/01/evolution-of-pc-enthusiasts-addiction.html
http://wolframpc.blogspot.ca/2012/01/evolution-of-pc-enthusiasts-addiction_28.html
However, to answer the question, I have a pair of 5850s overclocked to 5870 performance. It's roughly in the 7970/680 performance area depending on game/benchmark, generally just shy of that performance. Definitely no need to upgrade for at least another generation since I'm running all games at maxed out settings at 1080p including Witcher 2 with Ubersampling.
If you feel like friendly benchmarking, there's a series of benchmarking threads going on at Tom's Hardware.
http://www.tomshardware.com/forum/347472-33-unigine-engine-heaven-basic
http://www.tomshardware.com/forum/349133-33-cinebench-bench-thread
http://www.tomshardware.com/forum/349163-33-3dmark-vantage-scores-thread-benchmark-thread
These are my Unigene results using the Tom's benchmark presets:
P8458 in 3DMark 11
P28260 in 3DMark Vantage
Pretty decent results for a 2 year old PC.