are you kidding me?... if you are skiing park, edge damage is all part of it. its why you have skis specifically for rails and urban, if this kid is going to be doing "summer sessions" in his yard, i hope he's not using his 05 06 tanner pro modles. why would be care about edge damage?
as for pvc sliding better, thats bullshit, you catch an edge on that and your fucked... i mean come on, its plastic. might as well stay to one mediam and just slide metal.