I have primarily rode Kawasakis (even raced an 1100 Zxi for a bit in the late 90s) the Ultra series will dominate with thier new engine...personally I have gone to longer hulled skis mainly because being able to maintain a speed of 60 plus in rough water is more fun than taking out a small piece and while having a higher top speed wont be able to keep up...My current is an 04 F-15X 1500cc four stroke in smooth water with my 260lb ass on it I can hit between 68 and 70 in rough water about 66 or 67 consistant and the thrust from the 1500 four stroke is way more fun than its two cycle brethren