I have been thinking about updating my ride from a 01WR426 to a 05WR450, YZF450 or a CRF 450R. I do 50% competitive trail riding, 25% riding with my 7 yr old (CRF50) and 3 yr old (Jr 50) and 25% MX. I like MX riding but feel the bike is too heavy for this action. Others tell me I would not be happy with a YZF or CRF 450 on tight trails jumping logs and creeks. Has anyone rode MX on the 05 WR450?