Just spent last two weekends woods riding my new 09YZ450F after spending the whole summer riding my woods set-up 08YZ250 2T.
Only mods to the 450 were standard protection and Renthal
51 tooth rear sprocket. The thing is still not geared low enough in 1st for my liking, and still way fast in 5th. Next set of chain/rings I'll go with a 52 rear.
While there is no way to hide the fact you are riding a much more weighty machine, I must say it is suspended very well (after preferred set-up), and the bike went where pointed and was very plush. Best of all, WHAT A MOTOR!!! I really enjoyed the hard and seemingly endless pull. Wheel
-stands and climbs like a champion.
The 2T is definitely more nimble and really stands out in slow and technical terrain, but overall, I think the 450 is more all-around useful.
Really appreciated the 450 yesterday doing a long dirt road haul from the mountains (where we got shut down by snow at 5000ft), to the truck. Was nice to haul the mail at 450 speed with wheel stands just a crack of the throttle away. My pinger would have been 20mph slower and not nearly so enjoyable to cruise.
Again, for our terrain (mixed tight woods and long-haul XC) the 450 will prove the better all-around choice. At least until the injected 2T's come out!
One more thing, the price of new 08 and 09 YZ450's must be considered!