In addition to binding and edge corosion problems, another gripe I have about normal ski racks is that if you are driving in rain or slush, your entire ski gets coated top and bottom, tip to tail with the wonderful mixture of dirt+salt+sand thrown up by other cars on the road.
Now, if you ski on them this way, not only do you totally negate your wax job, but you can drive this abrasive muck into the wax/base. Unfortunately, this coating of muck is often dried on by the time you get to the ski area, so what are you going to use to clean them b4 skiing? Well, its cold out, so water will freeze, snow doesn't work that well, etc. etc.
My solution: After years of owning "normal" ski racks, I now have a nice big Thule car top box to throw everything into, and these annoyances instantly became a thing of the past.
Tom / PM