Bought an 07 crf250x a few weeks ago. Have 330 miles of tight and rough single track on it. (and lots of mud)
I am thrilled with it, just what I wanted. My last two rides were an XR400 very modified, and a CR500 Extremely modded. So moving "down" to a 250 had me concerned. I'm a big guy and this bike is doing great. I ride from 8000' to 12,000'+.
It is fun to throw around, blasts through the tights and is exactly what I hoped for. Won't be a high speed runner in the desert or long straights, but for mountain and Moab riding it is perfect.
You are smaller than me and I doubt you ride at a higher altitude, so enjoy your ride.