I am of the opinion the XR600R is perhaps the best do all M/C ever built.
I spent years trying to build a Bike to ride to work/play and race(Usally an alchohol induced thought--Egged on by my riding partner.)
THEN-------I purchased a '95 XR650L-------
Then started transformation.
STRIPED Everything off that was not needed. frame tabs,smog crap haust,stock forks and shock.
Replaced suspension with XR600 pieces(I revalved,springs etc).
built my own pipe center section.Installed Super Trapp.
Fabricated my own dual light system.Rewired complete.(stock wiring harness almost 5 lbs).
Installed HRC 628 cam,springs etc.Degreed cam.
4 gal IMS tank.custom lowered seat.
The result------285 lb(dry)ELECTRIC START XR600