Yes, I have replaced door skins with W&N. Verdict? They are a very good basis. The fit is precise, just one of the corners and the top needed a little metal trimming. A Dremel worked perfectly in that corner; you will not notice how much it needs until you have started the folding process.
I have not used an alloy one as mine is not a CSL there is no need; and steel is more resistant to dents, etc. 3/4 of the skin is folded around the frame but the top is welded on. I wonder how those alloy ones would attach the top ridge to the steel frame. Glue or spotwelding with special strips?
Folding the skin nicely is quite difficult, the metal is strong. I used first a block of wood and a good hammer with the whole lying on a couch pillow to get it going. In the final stage a clamp device called an "verzettang" in Dutch, not sure what the English word is, to get a nice sharp fold. This did create some imperfections along the bottom that my paintshop wasn't too pleased with - but they managed to get it straight.
Finally, the W&N does not include the reinforcement around the door handle and not the metal piece that the handle limiting plate bolts to, so you need to transfer them from the old door. Also the holes for the waist line trim, mirror and rubber buffers for the door handle are not in the piece, you need to measure, line them up and drill them yourself.
It took me about a day to get one in place. Well worth it though, doors usually have rust that is otherwise very difficult to repair properly, especially along the top.