I beg to differ a little on the opinions of 450's being no good in tight single track.
I have owned nearly all 2t's up until my GG450 and I reckon it's one of the best single track bikes I've owned, yes it's a bit heavy but as long as you are moving it's no prob. The engine is so user friendly, I find I can ride the GG longer in the tight stuff than my KX250 that is set up for bush.
But I'm sure Gas Gas designed the 450 for this in mind.....