I had the chance a couple weeks back to ride a CRF450. I have to say it is the easiest dirtbike I have ridden. It starts easier than a CRF150 (seriously 1 light kick). It has awesome 4 stroke traction and super handling. I did a couple laps at my friend's track. This track doesn't have any real jumps. Its just both sides of a really big hil with many turns, hill climbs, off-camber and whoops. My 500 will easily out pull the 450 up the hills, but when it gets technical the 450 feels so much tighter and lighter.
Overall for anyone riding MX tracks or really tight, technical stuff the 450 is the way to go.
Of course if you ride open areas, dunes or straight up hill climbs, get the 500.
And yes, I DID beat the guy in a dragrace up the hill
