I've got a '96 360 EXC, which has a larger tank,(like an XR), a wide ratio transmission,(like an XR), a heavier flywheel, (like an XR), but has about 10 more H.P., and weighs 50 lbs. less.
Once you get used to the differences, you'll find any of the KTM EXC models are easier to ride than your XR. More power, lighter weight, better suspension, and lots of bottom end, but with a rippin', top end that you'll never get with the 4-stroke.
I've had both, and I don't regret switching to the KTM 2-stroke one bit.
( By the way, don't even consider the 360/380 until you get some time on a 250. I went from a built 500 4str. to the 360, and it took me a couple of months to get used to the 'hit!':p