E6400 is very superior. I had the E6300 (1.86ghz) and ran it at 3.43ghz on stock volts for a couple years until I sold it. That thing was a beast. To this day I have never seen such a high overclock on air. I nearly doubled it's stock speed.
10% better than the intel stock cooler
its only 10% better, so it still stock. get a Hyper 212+ and I'm sure it won;t break your bank. Its great for OC'ing and easy on the wallet.
Alright Got it Cant Wait to overclock this thing..!