I want to say up front that Proball is easily the best paint that I've ever used. First impressions were great considering that it came in a shipment with two cases of other brands of paint, and they both had breaks in them. The Proball paint was perfectly round and clean.
I used the paint through several games over about three months and they stayed fresh for the whole duration. The paint shot well every time and never broke in my gun. I did have a few bouncers though, but most of those were in poor weather. Other than that my only complaint is that the mark from them is fairly small, but luckily it isn't so bad that it's hard to tell if it broke or not.
Proball is some of the best paint I have ever used and I will undoubtedly continue to use it in the future.