My son is a 12 year old novice rider. He has some desire to get into racing but I don't see it being anything too serious. Mostly, we'll be riding together on trails and such. Both bikes are about the same height for him. The TTR has the electric start which seems like the key difference to me besides, of course, the engine size. Is there a big difference in power between the two bikes? Reliability? I'm buying used but both are relatively new and in good condition. Presuming I can get either one for roughly the same price, what would you recommend?