Illuminations: Viewing area on the bridge at the Morocco Pavillion. Very nice view in my opinion. Twice we've been the only guests there; once it was PACKED! Depends when you go and what the weather is doing, but you must book.
Wishes: It's the area down the steps outside the Plaza restaurant. If you get there early, it's worth it. If not, your view is relatively obscured by hanging flower pots, lamps and branches of trees. It is only the small section, when facing the castle, to the left. There are about 6 or so tables with chairs. We went down 2 hours before wishes this year and had we not gone so early, we would have had a difficult time finding a decent vantage point within the area. If you skip one, this is the one to skip as you really do need to get there early anyway so there is no time advantage over staking out your own spot in my opinion.
I managed to get some fireworks photos from both so for me it was worth it as that was my main objective on said nights.
http://www.flickr.com/photos/2tiggies/7987152599/
Wishes by
2Tiggies, on Flickr
The reason you only see the top part of the castle is there are trees, bushes and all kinds of other stuff in the way below the bottom of the frame of this picture. It gives you an idea of your view. That was standing right up against the railing (I literally had the tripod legs pushed through the railing onto the grass on the other side).
For Illuminations it was great. I do have photos of the actual area but would have to sift those out. It remains the better of the two locations; if you must pick one, go with Epcot.
http://www.flickr.com/photos/2tiggies/7990660796/
Illuminations from Morocco by
2Tiggies, on Flickr