So far, this cpu has been a vast improvement over the FX 8320. I had the 8320 overclocked to 4.3 Ghz and this i5 has outperformed it completely without any overclock. I no longer have frame drops where I once did. I also feel that the computer is generally running smoother, but I refreshed Windows so its hard to tell whether this is the cpu. As far as gaming goes though, which is why I bought this cpu, it has been performing beautifully.
Cons: Doesn't warm my room up as well as my old Q9650 rig.
But in all seriousness, I wish there was an option to buy the chip without the cooler. This would reduce the price (not to mention waste) by a non-trivial amount. I'm sure most of the people who purchase at this level toss the stock heat sink in favor of superior solutions, especially for the "k" series processors which imply the intent to overclock.
Other Thoughts: I have this running with an ASUS Z97-A and a Cooler Master Seidon 120V. I was able to overclock the turbo from 3.9GHZ to 4.6GHZ and REDUCE the turbo voltage from 1.2V to 1.12V. Idle temps are around 26C and full load (Prime95 small FFT test) temps are from 60C to 65C. This was truly a great purchase, and I would highly recommend spending the extra $$ for this CPU.
I chose the i5 simply because I don't have a need for more than 4 cores. I might upgrade to an i7 at a later time, but at the moment most games cannot utilize more than 4 cores. I currently have this overclocked and it runs great.