I hate old balls. I've never played 4.0 or 4.5 league, but I can only wonder how terrible the balls are by the time you reach halfway into the second set. I definitely notice a lack of action on my serves and my forehands look a lot less lively even after one set of play.
I'm also not opening 5 cans of balls per week so I dont complain about it.
If I had my way, id use a new can off balls for every set lol.
"In the 1980's two men dominated--sometimes each other, most of the time everyone else."