We test drove a 3D last weekend after riding traditional stand-ups for several years. The 3D is more stable than traditional stand-ups due to its size, but that size translated into an ability to go much faster standing up in high-chop conditions than is possible on our smaller stand-up skis. The size/weight of the 3D eliminated the pounding we usaully get from our stand-ups without eliminating the fun. Regardless of the size of the 3D, we got good air over the ski boat wakes common on inland lakes. We loved being able to switch from vertical mode to kart mode! The kart bucket seat worked great and really held us in place on high-speed spin outs (intentional, of course). The moto seat was ok, but we liked the other two modes better. While we had previously said we would never get couches (i.e., sit-down skis), we were so impressed by the 3D we will likley purchase two, one for me and one for my wife (who likes to participate herself, not just go along for the ride). Lastly, the price makes it easy to purchase a pair!
While I can't compare it to an XP, I did prefer the stability of the 3D at high speed in kart mode as compared with comparably powered traditional sit-down pwc's owned by friends (Yamaha's and Kawasaki's).
