I haven't used them, but here's a few things to keep in mind:
-Illuminations is best viewed when you're *not* downwind of the center of the lagoon. Most of the time you can gauge where the wind is blowing ahead of time and choose a viewing location accordingly. Since the FP+ viewing area is a set location, you run the risk of the wind blowing in that direction. So then you either tough it out with smoke in your face, or find a viewing spot elsewhere, thus wasting the FP+.
-The Wishes area is a bit off-center by the Rose Garden, as mentioned above. Personally I wouldn't bother with it. But when the Hub construction project is completed and they start using the two new dedicated parks in the southern end of the Hub immediately on either side of Main Street essentially only a dozen yards from my preferred viewing spot now, I might rethink my outlook on it.
-Rob