I did this to my GT, for $208 Cdn, it was entirely worth it.
For anyone else planning on doing it, you will need the ski's, good time to change carbides if you got a few miles, I would get the rubber insert on the MnTn lite skis, the GT's was too small (the rubber piece that sits under where the ski attaches) and make sure to get the new wider pins and spacers.
Huge difference in deeper snow.
-Steve