We bought the X14V for the same reasons as mramerman. Our neighbour has an X15. The X15 is definately better for wakeboarding and for carrying lots of people through the chop of a good size lake, but it's not the main boat you'd want to ski behind if you are a serious skier. IMO, the 14V is a better compromise for the skier.
2012 X-14V, 5.7l Ilmor MV8, A plate, pro package w/ ZFT-2, heaters, stock everything else.