I dont know where you guys get the preformace loss from. I also have a 2003 seadoo gtx-sc with around 100 hrs into it & I have never had any problems with it at all also. It is still stock & no preformance loss. They are banning 2-strokes from production beacuse there exuast put oil into the water, but I like my 2001 gtx because you can do better spin outs, But I hate starting it in the mornings. Ive never run a yamaha so I cant comment on it. If they ever come out with the 300 hp one I will defenantly take a test drive.