This is one of my favorite things, too! I think they're usually biiiig improvements (i.e. "A song for XX" - "A song for XX 030213 Session take 2") and are much more powerful.

There was an alternate version of "HANABI" that she performed live, although I don't remember which show it was. It was really pretty, although very different. I think it was in a major key, too, as opposed to the original minor arrangement.

There were several other tracks that were redone for A BALLADS, also, including "YOU", "appears", "M", and others. Incidentally, "M" is the only re-make I've ever hated. The original was much better made, much stronger.