How good is this CPU?

While the i5-2500k is only $10 more than your budget at microcenter, you may not have one near you. The 975BE is a fine processor but cannot match the i5 in raw computing ability. The BE will game just fine if thats your concern while the i5 will do equally (or better in cpu intensive games) as well but surpass the BE in cpu intensive applications like editing/rendering video.
 
be nice to know what you're trying to put together and what your budget is....... however....

I have a lot of different hardware to mess with. If it's AMD you want I would get a 955 or a 965 and save the 30 or 40 and put it towards something else. You really won't notice the difference.

I game using a 775/q9550 and it's quicker than anything AMD has to this point. Sorry but true.

If you don't have anything set in concrete I would look at the 1155 processors. Quicker yet.
 

I have had both the Q9550 and the PhII X4 980BE. MY findings are that Tom's is right. But we can agree to disagree.
 



The Core2Quads and Phenom IIs have very similar clock for clock performance thus the higher stock clock speeds of the Phenom II 975/980 make them rank higher on the tier list. They both top out in the ~4Ghz range overclocked though.
 
Right now my PC has a Athlon II X2 at 3.0 GHZ which I believe is bottlenecking my ATI Radeon 7850 oc edition. Dont want to upgrade the motherboard just yet to except intel processors.
 



A Phenom II x4 975 will not bottleneck an HD 7850.

Your power supply is a very good one and will handle everything you listed just fine.
 

I just sold my Q9550 w/HSF on ebay. I was shocked at the bidding war for it. I was able to get almost as much as I originally paid for it new.
 



I know it. LGA 775 was around forever it seemed and alot of people out there still don't want to upgrade their whole system. The 9xxx series quads are still great chips if overpriced a bit. I have never seen a CPU line retain it's value like they have though.
 

I recently bought a refurbished desktop with a Q9550, and I am very pleasantly surprised at the great performance at stock speeds (no OC)!