I throw a set of skins on my Kastle MX 88's w/ Marker Barons and heap up the mountain here at least once per week. Yes, they are heavy. Yes, they ski great. Yes, people look at me like I'm crazy.
The answer to your question depends on your motivation. I wanted a way to get out and smoke myself while enjoying the outdoors, so carrying the extra weight isn't a big deal. I could care less about speed on the way up. This wouldn't be the set-up I chose for a long trip, though. Maybe an overnight hut trip, but not much more.