I've ridden them both and I feel the 150 is easier to ride the engine pulls longer and smoother with less shifting. I bought the 150 and I love it my son rides it too he's 14 now, but he's a bit bigger 5'11 and 165lbs. He never rode before and was able to go woods riding with me the first day on it. NO WRECKS either... Jumping on the 150 can be a little hairy. It bottoms on larger jumps. I ride the wheels off on that thing. Whichever you pick I wish you and your son many years of great days riding together.