Pretty much said it all already. With higher map nav you should be able to upgrade to:
Elevator - Shows team mission elevators
Exit/Entrance (Low req. Handy for those missions with just square rooms. I hate those!)
Custom Pet color - Allows you to choose in your pref file the color you pet shows up as.
Bookmark - Allows you to bookmark the map with a right click -assign. It then takes a /bookmark "Whatever you'd like to name this bookmark" command. Whenever you hover over it you get "Whatever you'd like to name this bookmark" instead of coords.