Wishes is DEFINITELY better in the MK, or on a boat in front of the MK than in the CG or Narcooses. The view from Narcooses is better than the CG IMHO.
At Epcot the view from the three "inside" places that I can think of to see Illuminations from is partially blocked, and you can't hear the music.
Personally I prefer to dine and then head out to see the fireworks for many reasons. First, there are extremely limited tables with window views in most of the restaurants, so your chances of getting one are slim to begin with. Next, I hate it when I'm trying to eat, and have someone standing over me to watch the fireworks. It's rude and disgusting. Also, the restaurants get so full during those times that service diminishes. And last, the view is just generally better from other places.
Anne