And then spend 20 minutes reassembling the board to go downhill again Sure, they are reasonably efficient for yo-yoing (fat skis + skins are about equal), but for any non simple terrain they suck, and so do the fiddly parts get lost/broken mechanisms.
Having splitboarded in the backcountry a bit, I'd have to agree, esp. in regards to yo-yoing. I got tired of:
Them:
Rip skins - go.
Me:
Rip skins - wait up, I gotta put my board together