I do beleive I did answer this. It may not have been directly but, I have mentioned I rode both. I personally liked the 250f better than a 450f. The 250f rev similar to my 500. Just less power and overall speed. The 450 revved slower to slow actually and still has less power. I prefer the faster reving 250f even if it has less power than the 450f. I have ridden a 2010 KX250f, 2005 KX450, 2005 YZF250 and YZF426. I liked the 2010 KX250f the best out of all of them. Oh and by the way, woods and mx track.

If and This is a big if. I ever bought a four stroke it would be CRf or KX 250f over the 450f.
James have you ever rode even a steel chassi CR or KX500? How would you like to test out a 2010 CR500af. I do beleive SH has 1 or 2 used ones for sale. Maybe AJ will let you test one out. I would be glad to let you ride mine. if I ever get out of this rotten state of NY.