i race motocross and enduro`s myself...
had alsorts of bikes but i swear by KTM! such a solid bike
and i have a 2007 250sx (two stroke)
and a factory edition 450sx 2009 (four banger)
in all honestly although four stroke have some low end torque u cant beat the mighty 2-stroke punch!!!! im sure whatever bike you have it`ll serve you a good time everyone has there own opinion but to be honest there all good in there own way! happy riding i say!!!!