Well, pvc cracks really easy in the cold, and it's really slippery and hard to grip when you want to do switchups or spin out. I bought some high-density polyurethane for a 2 ft. wide 16 ft long box, and it cost me $90ish bucks, but that is a ton of plastic because the box is so big. I would reccomend that, it's worth it in the long run, because it's super durable and you never have to replace it. The only thing that I regret about it was not putting coping on, becuase any plastic box without coping is hard to grip with your skis. Definitely go with polyurathane if you plan on keeping the box for a while.