Belt drive has several advantages. Stronger, lighter, simpler. Better throttle response both on and off the gas. Buddy of mine who has a ton of time on the 13s told me they handle better. Even easier to roll over and transitioning from side to side is effortless. He also said that you could walk the nose of the sled up and down in the air just by rolling on and off the throttle, he didn't have to change his body position. He compared it to a YZ250. Also said it felt like it had at least 10 more HP and the engineers told him that the sled he was riding had a 2012 spec engine. Major reason I am trading my 12 for a 13.