Its hard to upkeep metal like a ski mountain does. In my experience PVC slides way faster than metal, and doesn't rust. I think its cheaper too, so you can spend less money/build a longer rail.
"I kinda felt like a dork just now...I was taking a dump butt naked except for my socks, goggles, and a condom beanie while talking to you and trying to open a bag of peanuts": thefilmerguy, on the phone with me
Check these out and tell me what you think!: