I just spent a whole week riding the XT on-road and off-road, and I can't say enough good things about the bike, my ride report is here
I'm still going to be posting a detailed report this weekend in that thread and a write up about the bike, so stay tuned.
So far I can't be happier with the performance of the XT, it goes 70PMH on the street (I got it up to 78MPH on a dowhill) and it seems to do off road pretty well too (it's my first off-road bike so unfortunately I can't compare it to any other off road bike).
I bought the bike new end of September 06, and I have 1360 miles on it now
I come from sport-touring so I'm used to spending 12-20 hours on a bike, I've done some long days on this bike (only 8 hours) but it's not a problem for me, I think it's comfortable enough, although fast speed limits on straight roads are even more painful then on my crotch rockets, because I can't get on it and get through it quicker, twisty paved roads are still very enjoyable.
My favorite traveling speed on this bike is 25-45MPH. I'm going to do something with the exhaust, first I'll do the mod they talk about on the XT225.com site, but if I can't get more ponies this way, I might try an after market exhaust. I'm planning on adv-touring this bike, I think it will do the job well with some work.
On this last trip I had to ride paved roads at 15% incline, steep dirt roads and I've even been caught riding in 40-50MPH winds. The bike performed well, I was actually amazed. The only time it wasn't cooperating, was after sitting in the ran for 24 hours, it started but would die immediately if I didn't gas it, so I had to run it for a few minutes and give it gas manually to warm it up, the choke didn't seem to work when the bike was wet. Even after sitting outside at night in 20-30 degrees, it started right up the next morning.