My other bike is an 06 XR650L. I've done lots of mods to it, CRF forks, FCR carb, 672 kit, cam, big brakes, etc., and stripped off a lot of weight. It works really well, much better than stock, but is still heavy. The idea of something that was the exact opposite in some ways (shorter, lower, quicker steering, lighter) yet having some of the good characteristics (low revving, linear power, super reliable) was really appealing.
On the other hand.....it's a playbike, not a race bike. Kinda slow, budget suspension, low tech motor. But I kept coming back to a few things: the short wheelbase, 6 speeds with fairly close spacing, a Honda, and the mild state of tune. The wheelbase and gearing would make it competent with more modern bikes in tighter stuff, perhaps even be an advantage. The XR factor meant it would be super reliable and easy to mod, and the mild state of tune meant that I should be able to get more power from it easily. Just a simple compression bump and pumper carb would be big upgrades. A CRF250 has considerably more power, but the XR has a good delivery and probably a lot of potential. Here is a graph of the two:
If you run them in the upper half of the range, the XR will get smoked bad. If you run them in the lower half, the XR is as fast or faster. If there is on thing about the CRF that really stands out, it is not the peak HP, rather it is the fact that the power curve is really flat for a wide spread at or near the peak HP. The XR really drops off.