Sport Jets = yuck. Thats just my opinion. Actually Ive been pretty impressed with the SJ's Ive been around. They seem to move the boat along at a pretty good clip. The only boat boat Ive ridden in that has a SJ was a 19' JetCraft Yukon. It jumped out of the hole fast and would run about 48 mph at top speed.
Im still for a V8 inboard or a big outboard. One thing I would look at before buying any motor is the cost of maintainance.