Now this is a GREAT question! Basically, a stiffer snowboarding boot will restrict movement of the foot and ankle in trade for additional support. My stiff boots are awesome for freeriding and boarder-x but they are not as cool in the halfpipe since I can't seem to get all the grabs — just cant flex and tweak enough, ya know. Conversely, a softer snowboarding boot will allow almost full range of motion, but be careful on the run down to the park, you moght not have enough support for handling things like chunky snow, slop, compressions, or other terrain changes at higher speeds!Rock on!F.R.