The factory floor liners don’t appear to go upward on the sides like the WT or Huskies. They have a good rubbery feeling and appear to be quite heavily made.
I have always had a 8’ box, so never needed a slider. My brother was trying to get on a spot at a state park and broke his back window out and creased his cab a couple of months ago. All it takes is a split second and it can ruin your day. We both have ten year old trailers which don’t have the rounded corners. Since I ordered the 6 3/4’ box I decided to go with the Demco auto slider. Don’t need the worry or excitement of forgetting on a hard park.
I have WT in my f350 now. They have been pretty good, except slippery. I have ordered WT in the HP version for my order, they are supposed to be more like the Husky WB’s and not so slippery.