You're gonna have to decide on what you want more, on road or off road. The 250 are gonna be lighter and more dirt bikish, then the 650. But for riding on the street the bigger one is nicer, you won't need to shift if you need to speed up in traffic. My two sects go for a bigger one, as you'll grow into it for your riding skills and not wish for a bigger bike. But that would be for street. For dirt can't help you. Sorry