Got a chance to get my new 450FX out on Saturday. The trails we were riding were a mix of tight/technical and slightly more open, no real super fast flowy stuff. As I do with every new bike I get, I pulled this one apart to grease up all the moving points and I have to say I'm less than impressed with the dealership's "setup" and I'm really glad I didn't pay a setup fee since the front axle pinch bolts weren't even tight and the tires had over 30psi of air in them. That should have been my first clue, but the one thing I didn't bother with at all was suspension settings- I wanted to ride the bike some and let the suspension break in a bit before I started messing with clickers. In hindsight, I should have verified that everything was still at factory settings.
The good- amazing power that is very useable. When the going was slow I could easily just putt along at my leisure and let the bike do it's thing. The power rolls on very smooth and doesn't have any big surprises or hits at low throttle openings. When things open up a bit, just crank the right grip and the old girl wakes right up and takes off like a scalded dog. When you need to slow down the bike's engine braking does most of the work for you most of the time. Transmission was amazing... I loved being able to really slow down in technical stuff or on switch backs and not have to worry about stalling the bike or feathering the clutch. There's plenty of power on tap to make good use of the wide ratio trans when riding roads to connect trails, I never had it anywhere even close to wide open throttle and was still able to carry plenty of speed.
The bad- Nothing that can't be fixed! The suspension seemed a little twitchy when there were a lot of rocks or roots, but overall the bike felt very stiff on both ends. I want to make sure the clickers are at stock settings, then once it gets a few more hours on it (around 3.3 right now) I'll start messing with sag and clicker settings to get it dialed. The only other "issue" I had was hitting neutral between 1st and second sometimes, but the shifter feels a bit high so I'm going to try moving it down 1 tooth and I suspect that will take care of it.
This bike is definitely still a YZ and seems to prefer to be ridden more aggressively and really requires you to have good riding position (which is one of my weaknesses). It's everything I wanted my old 06 YZ 450 to be and does everything better than I can remember the 06 being able to. Although I claim not to be a fan of e-start on a dirt bike, I have yet to use the kick starter once... I really think this is the ideal bike for the type of riding I do. Very happy with my purchase!