My 13 yo son rides a 97 KX100 which is in decent shape for its age, but I'm thinking about upgrading to a newer model. Is the engine/suspension alot better on the 2010 KX 100? He rides some trails, but has been riding more and more motocross tracks lately. Also, what about the KTM 105? Is it that much better a bike? I'm not interested in the Honda CRF 150; would like to stick with a two stroke.