I think it is hard to compare as each performs a diffent role. I have both and figure that the rail scratchers are more suited to assist with cooling while the ski scratchers are better at lubing the hyfax, especiallt the front (ahead of where the rail scratchers mount).
My experience has been that my hyfax tend to wear out first just behind the front sweep of the rails. The first place that weight contact is made on a flat surface. I don't think that I have ever seen the hyfax have increased wear anywhere toward the rear of the skid.
I think having both has helped me in both areas and I'm glad I do. Good luck. EW
