Hi, I own an 01 wr426f and want to buy a Yz 450f to add to the collection. My question is do i buy a 03-05 with a 4-speed or do i buy an 06 with a 5-speed. I am hoping to get into mx but also want it for the occasional bush ride as well. Buying a yz will there be a fairly increased power hit to the wr? How would the 4-speed hold up in the bush and is it geared well for mx tracks? I would prefer to buy an 03-05 (because there cheaper)but if the 06 is alot more versatile ill just wait and get one of them. Thanks.