Most of the garden view concierge rooms look out over the parking lot and convention center. In addition, there is one slice of rooms that look out over the courtyard where the YC wedding pavillion is located. None of these are "bad", but just not terribly exciting.
The waterview rooms either look out over Stormalong Bay and across to the Boardwalk or over the back courtyard where you leave the hotel to walk to Epcot or the MGM boat dock. I always ask for a water view room which looks out over Stormalong Bay, as you can see Illuminations pretty well from those, as well as a better view of the Boardwalk. The only "bad" waterview rooms (relatively speaking) would be some of those looking out over the back courtyard which face the wrong way (away from Epcot) and, thus, get no view of Illuminations.