The last Nvidia GPU I owned was back in 2004. Since then, I've owned ATI/AMD GPUs: 3650, 5570, and a 6850. I wouldn't say I'm biased toward either side, I just buy whichever card offers the best bang-for-my-buck at time of purchase. I recently purchased a GTX660 and am a little disappointed in both the look and limited functionality of the Nvidia control panel. Namely that the Nvidia control panel (NCP from here on) UI doesn't look like it's changed in a very long time. There also seems to be some general settings not available on NCP that I had in Catalyst Control Center (can't give any specific examples at this time), but that may be due to my inexperience navigating the NCP. Also, CCCC even offers the user some overclocking/tweaking/monitoring/fan control options whereas you seem to have to employ a 3rd party program to accomplish these same things on Nvidia GPUs.
So what gives? Am I missing something?
Main: i5-3570K, ASRock Z77 Pro4-M, Asus GTX660 TOP, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
HTPC: A8-5600K, MSI FM2-A75IA-E53, 4TB Seagate SSHD, 8GB 1866MHz G.Skill, Crosley D-25 Case Mod