For the previous RM250 rider, thats the 2T I currently own, a 2005 RM250. So you are saying while this bike is significantly better, it is not going to be a game changer as far as the powerband is concerned. Correct?
Well, let me put it this way. My friend has an RM250 06 that is ported, polished, Wiseco-Piston, Pro-Circuit system, Hinson Clutch system and Vforce reeds. It is very fast, but my 12' KTM250sx feels as fast or faster completely stock.
The comment at being a game changer was focused on your reference to feeling like a 450 four-stroke, etc. If you like your RM250,then you will love the KTM. You just won't hop on it and feel like you've never ridden anything close.