I wouldn't say that I really feel a big difference between balls but I have found a real tangible scoring difference. I was wondering the exact same thing and at the beginning of this year ran an experiment for the season. I belong to a private course and play almost everyday during the summer. Three days a week I play by myself. During those rounds, I played two balls independently for the entire round. I used a TP5x and a ProV1, different manufacturers and different styles of balls. After playing 30+ rounds in this manner, I found that I played the ProV1 to a handicap index of 10.2 whereas the TP5x played to a 11.5. That is significant. I'd been playing TP5x for the last couple of years, I've switched exclusively to ProV1 now. In looking at my data, I see that the biggest difference was on approach shots. I'm not a big hitter, 7 iron carries 160, but I do hit it straight. I just seem to get more consistent distance with a ProV1 off my irons.