MC gives you the choice of writing tags back to your files, or just keeping them in MCs own database. If you are retagging a lot of stuff and experimenting it can be worth just using MCs own database until you are happy, and then getting MC to write your chosen tags back to the files. Its up to you.
There's no real answer to tagging classical music, you just have to put in the work to get it the way you want, but it probably isn't necessary to do it on a one-by-one basis. If say you have been inconsistent using two spellings of a composers name, you can select all your tracks that have the spelling you don't like and change them in one operation to the spelling you prefer. There are also powerful query wizards which should help you find stuff that doesn't fit your chosen pattern. And because you can set up different views to your heart's content and MCs tag changes are almost instant, you can see the results of any changes immediately so you can knock your tagging into shape much quicker than in other systems which may require a long rescan.
Having done all this it's not impossible you may prefer MC for playback over Amarra too, but you are not committed!
