To be honest, I haven't used it --yet--
But what I'm interested in using it for are things like subtle face movements or other skin or tiny muscle features for an animatronic project. I'm an animation major, but, of course, I also build robots. I thought, why not put the two together and build animatronics?
I've thought to doing an animatronic alien or dinosaur or something for Halloween so once I get the time, I think I'll be putting some muscle wire to use in that respect. A good friend of mine who goes to the Art school I attend actually creates professional puppets, so I'm anxious to query his method for puppet making. Then see if I can automate it.