I once played the same ball (prov1x) for seven rounds, without losing it. Shot some great scores with it, which prompted me to keep using it.
The cover was still okay (although scuffed) but it performed no different than the first round I used it. I just cleaned it up, remarked it with my 2 dots, and I never noticed a difference in performance.
Something you couldn't have done 25 years ago with a balata. Or even a 2-piece back in the day. Urethane covers changed a lot regarding endurance.
I still think the most durable cover ever is the Srixon 3-pc (Tour Yellow) Z-star. And a great performer.