A suggestion to make working with the wonderful mp3tag even smoother:
Enable switching the view between the different tags just by one mouse click. ID3Tagit had a button where you could do this.
Currently, you first have to go to Tools > Options > check the box for the tag(s) you want to read, then hit the refresh button. You have to do this every time for each single tag, which is kinda annoying. For example, when you have mp3-files with varying data in the id3v1 and id3v2 tags, you could just hit the button to switch the view between those two tags, instead of going into the options menu.