Gdog, unreal is an understatement. I rode/raced my CR500 for many years and thought it was great. Then last year I get the KX and its like "what the #@%$&*" !!!! What I would have aprroached with caution and the Honda, I barely hesitate with the KX. The straight line grip and rip ride through open desert is priceless. If that doesn't get your adreneline flowin', check your pulse, you need help.
I've ridden with people that have newer bikes, I hear the comments like " she still runs, huh?" or "vintage class" or "my Dad had one of those". Then, as you said, lopin' along the trail between 3rd and 4th gear, someone on a 450/250 four stroke wants to step it up, drops a gear and tries to disappear, I crack the throttle, without down shifting, the after burners kick in, I fly by like their standing still, throwing a meteor shower of rocks, sand, cactus and sagebrush. Later as I stop to let them catch up, no one has anymore comments. Whats especially insulting, is this usually happens in a sandwash, and I'll blow by.......sitting down. Then, when they ask to ride it, I tell 'em "No, but your Dad can!".
Anyway, you get the idea.
I live in Rancho Cucamonga, and I ride in Stoddard Valley off the 15 fwy, and also in Lucerne Valley.
I have a couple of loops that I do out there that will definitely exersize you and the bike. Anytime.........