I see that Exmark has quit using to 31 Hp Vanguard and went to a 35 Hp on the 60" XS and are offering a speed up kit to increase the speed to 15 mph. I have the 05 XS with the 31 Hp and I am drooling to get my hands on a 35 Hp. Do we ever get enough? Now I just have to figure how to get it and dirty it up before the old lady notices.......... On a more serious note I bet the 35 Hp will get me through the whole year with a mulch kit. With my old 27 Hp I had to remove it in May. This past year I made it till August with the 31 Hp and removed it for about 3 weeks during the rainy season. The Lazer Z buyers will now get the 31 Hp and they are going to Love It!