IMO All-Stars are the best paintballs out there. Evil (I forget the name of their top brand) is pretty much the same thing. I'm all for having good paint. Look at it this way....the lower quality your paintballs are the less accurate it will be and the more you will have to shoot to eliminate someone. So in the long run taking care of your paint saves you money and gives you a decided edge in your game.
But on the other hand I don't flip my paint every other day or anything like that. I usually flip it about once a week. Usually when I'm going to go play or when I get home; that's if I have any paint left
Just keep your paint in a cool, dry place and flip it every once in awhile. I've had paint that was a year old (a mixture of Blaze and PMI Premiums) and had zero breaks and it shot surprizingly well.
And if you're using oily paint and you didn't wipe off the access oil take the time every few games and run a squeegee through your barrel to get that gunk out of there. You will notice an improvement in accuracy.