If the IPT were to wipe all rotation games right off of the competitive map, I'd be fine with it.
Games like straight pool, one-pocket and 8-ball, by making you decide what order to play the balls in, are more interesting to watch and to play.
Therefore, of 9-ball and 10-ball, the one I prefer is 8-ball (LOL)!
I truly believe that if the IPT makes it big and become the game's highest level of competition over the long-haul, the world of regional pool, which is where pro skills will be developed and honed, will embrace 8-ball. Under that scenario, nine ball would fade as a competitive discipline. Wishful thinking, I suspect.
If forced to choose between 9-ball and 10-ball as the mainstream pro game, I'd take 10-ball, entirely for reason #2 as noted by Joe T.