I'm a newbie of MP3TAG from Italy
I've used another MP3 tag editor called Eags On!, which I find really intuitive to use. Unfortunately it has been discontinued from the developer and it shows its age (no other file types support except mp3, freedb works 1/3 of the time, no album art support)
MP3TAG have a lot of powerful features and it looks to be actively developed and supported by the community. However I didn't find it much easy to use.
Maybe it's just my fault to be accustomed to the old program, but give it a try and compare the GUI differences.
MP3TAG wants to scan the entire MP3 folder every time, and it takes 10-15 minutes, plus I can't understand how to navigate between folders. It shows all my file in a looong list.
Why don't you add a windows-explorer like tree navigation on the left?
I suggest also to put the ID3 tag window in panes as well as file editing options, and browse them as windows options menus. There's plenty of space on the screen, many of the tiny icons could be replaced by the option panes concept.
Please take this just as a suggestion, I don't mean you have to throw away all the work, just a little polish of the GUI to be more Windows-like.
There's nothing better than try by yourself the editor I described, download it and compare