I had the 215hp 150 sportster before, and had plenty of power to pull skiers, tubing and alround good performance. I think for me I would have gone with the 255hp if I had a chance at the time, just for the factor of saying that I had 255hp, instead of the 215hp. As far as performance don't think you would really know the difference, the 255hp would probably give you a few miles per hour more on WOT, and may have alittle quicker response, is that worth the extra 40hp, that is something you have to ask yourself, they both have the supercharger that has to be maintained equally, maybe the difference is price between the two, I think it would come down to saying to your friends that I have the 255hp or the 215hp.