My buddys got a cr500, another kx500, 520 exc and another few 450excs, wrs. I ride a gg300 usually. I would definitely say that the 450s are out of the question unless you want your mind 2b more relaxed wile riddin. the 525 would compare mostly to the cr 500 in turms of power. the 525 is smoother with less vibration while more power is getting to the ground. suspension would go to whichever one is dialled for you but of the shelf ktm. I catch myself looking for more out of a 450. It reminds me too much of a 400. the power curve will never appear to be stuning and flying like your 500. the 450 compares more to a 250.
performance vs puting traction to the ground and your money were your mouth is
the actual drag race results 1through 4th gears gg, 520, 500s,wr,ktm. 5th, 6th 520,450ktm,kx,wr, gg, cr.
the electric starts are sweet as well as the 4st power thats on the ground.
My buddys cr is a 98 and we ride together constantly and hes aimed mostly at the 525 for his next update. everyone keeps having to much good to say about the 450 though. My personnal pick would be the 525 with one tooth of the countershaft sprocket. it wont bite back as abruptly then.