So I'm going to get the last two live albums later, in the meantime here's what I recommend for those who aren't completists but might be curious about these:
No Prayer: Skip it. The original CD is better and probably not that hard to find.
Fear Of the Dark: Get this one. Probably the best of the bunch honestly.
X Factor: The differences between this and the original are subtle, but it's still an improvement. The package is also very nice with the foldout booklet thing.
Virtual XI: So much better than the original. Having this is going to make me want to listen to Virtual way more often than I usually do.
Brave New World: Like X Factor, there are subtle improvements. Recommended if you really like BNW.
Dance of Death: It's still a little compressed but a major improvement over the original. It doesn't sound like they're pushing the limiter into the red at every moment. It's a nice volume and more space between the instruments. The music actually breathes on this, which brings out a lot of its under appreciated qualities. Fan favorites like Paschendale are no longer held back by a distorted master.
AMOLAD/TFF: I didn't really hear a difference from the originals, which is fine. Probably only for people who are big fans of these albums or completists.
And for the sake of completion (and since it fits in the box): Vinyl is the best way to hear The Book of Souls.
Keep in mind the only differences are in the mastering (loudness, overall EQ, stereo imaging etc). If you don't like the muddy reunion era mixes, don't expect anything different with these because they didn't remix them.