I have used Winchester, Remington, Federal, CCI, and Fiocchi (leadless) primers for years now.
I have had one bad batch of CCI small pistol primers, where my trusty Glock 17 would not detonate them on the first shot. I thought that maybe my striker pin spring was starting to go bad, so I switched to friend's Beretta M92, which has detonated everything, even the ultra-hard primers in GECO Safe Action Slugs (BAT) that make CCI's hardness pale in comparison. I still had failures to detonate on the first trigger pull although the second trigger pull did the trick (yes, I always checked the barrel to make sure that it wasn't a squib load).
I think I bought those primers sometime early in 2001, at a gun show in West Springfield, MA. Since then, I've gone through another 2000 CCI small pistol primers, and haven't had any problems, but for a brief moment in time, I was about to give up on CCI primers.