These play really fast and I haven't had any problems with the balls breaking. Love 'em!

Update, April 2008: Still using these as my primary ball and they continue to do their job - they keep their bounce well and rarely break (only after long periods of abuse, long after they should have been retired anyway). Some people that I play with think they are too fast, and feel like they are playing with "super balls." To each his own!
5 stars