If the friction were too low, the ball would slide instead of rolling. It certainly seems to be rolling to me (will be easier to see when we get special custom balls). If you think it's too fast, then need to reduce gravity or the table pitch. I haven't bought the pro version yet, and not sure if I will (just not that interested - I also never turn tilt off). Having an option to change table pitch or gravity would probably be fun though (so long as leaderboards are turned off when anything like that changes), so hopefully that's something they can do in the future.