agree with that harv.
  i got on pretty well with the WR, but like you suggest, i started small and progressed.  Although i see the likes of wr/ktm450 as middleweights, there's certainly a lot of progression to make from them onto bigger and better things!! 
 People adapt to off-roading in different ways; some are just able to get on with it and others struggle... i crew for a friend who races enduro, he took a ccm250 green laning a few times then bought a wr450 to race and finished 2nd! 
 So RR, probably best to start with something smaller as harv says, then see how you take to it.  And if you need a test rider.... 
