[Soundgod]

I wouldn't waste my time trying to watch Illuminations from anywhere but inside the park. I have watched from the concierge lounge on the fourth floor of the Boardwalk and only saw the high fireworks. You can see some of the aerial fireworks from various places around Crescent Lake, some rooms in the Dolphin, some rooms in the Beach, and some rooms in the Boardwalk. Sadly, you won't really hear the music and even worse, you won't see the inferno barge at the beginning and worst of all, almost half of Illuminations is the video globe, and the video globe only, and you need a clear line of sight somewhere around World Showcase Lagoon, that isn't blocked by trees or buildings, or you're just going to be standing around waiting for something to happen.
This isn't like watching MK fireworks from the Contemporary, or even from around Seven Seas Lagoon. Even if you walk to International Gateway and try to watch from just outside the gates, you're going to miss a good deal of the show.