Rod,
On stationary ramps they are fantastic, but I don't think I would recommend them on a trailer for 2 reasons.
1. I read many horror stories when I was looking to purchase them of people undoing the latch or unlocking the winch prior to the trailer being fully in the water and the ski ended up sitting on the concrete.
Another thought, If you do decide to get the teflon pads. I've seen 2 versions. The first is a set of 16" strips that have ridges the length of the strip. The ridges hold dirt/sand and can scratch the hull. That is what I put on the first ramp.
The other type is a single 6' section that is smooth. I'm getting those for the 2nd ramp.