I don't mind little cosmetic issues so much. This is out of necessity because I simply couldn't participate in the hobby financially if I sunk money into correcting all the cosmetic issues of my games. But I do keep them in a good shape as I can afford.

But I do mind little technical issues. Anything that affects gameplay negatively. Games not dead straight, flippers with poor action or not aligned correctly, bad kickouts and feeds, etc. If a game doesn't play 100% as designed it pisses me off something chronic. So all my games play great. It does make it difficult for me to enjoy other people's collections sometimes.