Get a second opinion.
Call a local dealer or two and find out who THEY send their trans to for repair and go there.
Here is an old write up from "Gilly" (a respected tech and past moderator) regarding teh 722.6 trans. You do need to change fluids. IMO 60k is prob OK. Use MB fluid for the 722.6, or the newer backward compatible 722.9 (G-Tronic 3353) MB fluid only.
http://www.peachparts.com/shopforum/showpost.php?p=702285&postcount=8