What kind of riding are you into? Track, Trails etc.? This will help my opinions. If you have got access to rentals and the coin, do as others have said, try them both out. I want to tell you to get a YZ426, but the bike is only as good as the rider! I cant get enough of mine. Truth is, the 426 has more sack than I. My last bike was a YZ 250 very light, very fast, and all pipe. Much easier to ride. The 426 is heavier with completely different power characteristics. It took me some time to to learn how to ride the beast. Im a 150 lb. rider, and the power to weight ratio works out just fine for me. The only time I notice the weight is when I lay it down on some hill side. It takes some sack to pick that bastard up. Starting it was a chore at first, I dreaded stalling or shutting it down, but now its a piece of cake. Over all the bike really hooks up well for me, Im in and out of corners much faster, it climbs great. Just cant get enough. One thing is for sure the YZ426 wants to be rode hard and fast. If you an animal, and got the strenth to spank the monkey, well....... you know the deal! No matter which bike you go with you will get your moneys worth. Thats my 2 cents on the 426 All I can say is good luck on you decision.