I started off mtn biking, then started BMXing. I enjoy both, but bmx'ers have way better style, mountain biking is full of hacks with no style, its a newer sport, its like skiing 4 years ago, the style needs to be developed. Ofcourse mtn bikers are going to go bigger , thats what the bikes are good for, but riding skatepark on a mtn bike is stupid. You dont need the stability of a bike that big in park, but you do need the agility of a small bike like a bmx. Mtn bikes in skateparks are just akward and pointless and break alot. As for going big, watch Garret Byrnes's Jersey roof gap in Little Devil Seek and Destroy. The bloody gap is off the second story roof of a school to a grass slop about 15-20 feet down, and he did it butter smooth on a BMX.