There are well known issues with wearing of fabric on the bottom of the slides. Prime Time has yet to come up with a solution other than put a tape similar to the existing bottom cover but the tape bunches up. Go to the Prime Time forum and look at the post by Platokidd and is titled "Slide out/underside wearing" which began in August. Many of those with issues now have their rig in storage for the winter and when it comes time to use again, the warranty will be out. Prime Time has remained pretty silent about any issues and those people are anxious on whether they will be covered by warranty.
I have a Crusader 330MKS and it has been without issue since I bought it in July of last year and about 40 nights and 6,000 miles but I see a small amount of wear on the fabric at the bottom of my slides. IMO, using fabric is a dumb move.