Customization of the tags that get shown is already saved per media type.
Ok, that's nice.
But...
Not all of my media types share the same sets of tags.
For instance, some of my videos will have Series, Season, and Episode, while others will have Album, Sub Album 1, and Sub Album 2. In MC11, I could set up my view schemes to show the relevant columns, then set the Tag AW to display the fields in the current view.
And apparently I was the only one who liked the ability to hide empty fields. It made for a great display of your tags, and one check was all you needed to show all of the empty tags for those times when you needed to fill them in.
Honestly, if you brought back those two options, I'd be happy. All of the other stuff I mentioned was due to complaints I'd read in here about all the other functionality that'd been removed.