Which boat are you considering? If you're looking at a VLX, or LSV, it probably makes sense to go with the Power Wedge. If you're thinking about a vRide or something along those lines, the manual Wedge may make more sense.
The main difference between the two is that the free-floating Wedge is going to adjust itself to the conditions (boat speed, ballast placement etc.) while the Power Wedge will allow you adjust it's position. The Manual Wedge gives you a great wake at any speed, but you don't have the control to make the wake steeper like a 210 at wakeboarding speeds, or bring the nose down at surfing speeds to make the pocket longer.
I guess unless you're looking at one of the entry boats in Malibu's line, or you're getting a boat that will be used for skiing a lot, with just a little wakeboarding, I would go with the Power Wedge. The adjustability, resale value and cool factor are probably worth it.