gday ; )
I came off a 00 wr250 a few weeks ago, and I was pretty impressed with the old one. The new one has smoother power and a bit more of it. But to me the suspension is the main improvement - overall handling is better than any bike I've ridden (mostly that's compared to various yamahas and the occasional honda cr). Including cornering, especially rutted corners. Stability, eg thru rocky ruts or whoops is also exceptional. It's plush over small stuff, and I've yet to bottom out the forks where I used to bottom out the old one fairly often. In short, I'm very impressed.
"What about Parts availability?"
No problems here in au. 90% of the time they have what I want in stock. The rest might take 3 days to get in.
"Does it bark or does it have a vanilla power delivery?"
hmm, the power is smooth and useable. The hit when the powervalve opens is there but it's not extreme.
"Brake performance?"
Better than my old one. The rear disk floats. Not sure what the benefit of that is. It brakes very predictably, but I think that's partly due to the suspension.
I'd still ask for a test ride.