I will happily and proudly diss a 426 and the new 450. Sure it is better...if not, Yamaha is an idoit. I will diss the others because as a second dirt bike, my 2000 WR400 which was bought 2 weeks ago basically new was 3500 bucks cheaper than a 450. I do not think that the 450 is THAT much better. Maybe if I rode everyday or if it was my only bike, but no the 450 or the 426 for that matter is not a huge difference over even the 400. FYI...I am wearing my fireproof suit.