I use credits to get the type ball I think is the best value. However I do get the free ones every once in a while and sometimes want to try a new ball. I think when you reach your last ball of whatever type and it runs out of "hits" the game should allow you to CHOOSE the replacement not default to the "free" ball. The difference in meter speed is impossible to adjust to mid round, I understand WGT wants to "sell" balls and with that in mind they should want you to choose a ball you bought not a free one, Everyone wins. My two cents.