Hi, I was wondering what, if anyone, thought of these. I rode one last night which had a 290 big bore kit and have to admit that it was probably one of the most fun rides I've had in a long time. The thing would just turn on a dime! It was such a difference that I almost didn't want to ride my 03 YZ450. I could ride lap after lap with out getting tired, and just kept smiling! It was nice to not slam into the berm but be able to come in and rail around it (or change to a tighter line). In the trails it was a blast too, you could adjust your line or adapt to anything with no problems at all. I've allways been partial to Yamaha , but this thing was just way more fun to ride. The big bore did really help, but power aside the weight that you felt was like riding a street bike to a BMX bike. In long straight section the YZ killed (because of the power), and it is nice to ride almost everything in 3rd gear, overall it's just not as fun. I allways thought that more power is better, but slowly I'm realizing that's not the case. I rode a 05 YZ250 (stock) that night and also came away impressed. I never thought that I'd like a 2 stroke power band, but this bike felt almost electric. Had more power that the kx four stroke, but wasn't as fun. Just as a note: I thought that the power of the YZ and the KTM 250 (2 stoke) I rode a couple of weeks ago were very similar with Yamaha I think feeling better (more 4 stroke feeling with the absence of and "hit"). I think that I almost rode the KX more that the guy that owned it last night. I'll probably ride my bike for the year at least, but I hope that the new YZ450 handles better than mine. Maybe I'll consider the Yamaha 250f, but I can't see it being better than the Kawasaki. It could be that I'm just getting older and have less to prove, that having fun doesn't necessarily mean having to have the fastest bike out there. Just some of my personal opinions.