I have compared Moving Pictures remastered to the original. Here is what I found:
The remaster had much better soundstaging in all three dimensions. The original's sound seemed to be a blurry mess in the center, whereas the remaster had better left-to-right soundstaging. It was hard to tell where Lifeson's solo on YYZ was coming from in the original, but it was clearly right of center on the remaster.
The transients were much more pronounced on the remaster. Peart's bass drum pounded my chest a little more on the remaster than the original. The opening kickdrum on Tom Sawyer just about blew my head off!
The remaster is a little more "forward" than the original. The original seemed to come from 3 feet behind my speakers, but the remaster felt a little more up-close and personal.
In short, I found the Moving Pictures remaster much more fun to listen to!