I'm an iTunes emigrant still trying to figure out a few things with MC. One issue is the Disc and Track number information. In iTunes one can (optionally) assign a Disc total and a Track total for any given album, and iTunes will show this as Disc X of Y and Track X of Y. I find that information useful and have judiciously tagged all my albums accordingly.
But I've not found a way of displaying that information in MC, either when ripping and tagging new CDs with multiple discs, or when importing music files that were ripped and tagged with iTunes.
Any pointers would be very much appreciated!