The first problem I encountered removed all the mp3s from one of my artist folders. Selecting a folder on the tree view seems to do nothing. Double-clicking it causes it to be scanned and contents shown on the right. I thought perhaps that dragging it to the right might do the same thing.
I tried this when there was currently nothing in the right side. Poof, all the tracks from the artist folder I dragged disappeared. I had to search my drives to find out where they went. They wound up on my C: drive within some new folder the app created.
I have just tried Tag-It. I can say that I am VERY pleased with it so far. My suggestion for Tag and Rename right now is to look at Tag-It and emplode, and copy their best features, eliminating the overlap that already exists from T&R. Tag-It and emplode handle multi-file tagging better. Tag-It allows editing of much more info than any other program I've used. emplode has the benefit of pre-filling fields which are common between multiple selections.
Tag and Rename does have a very useful Auto-numbering feature and its table cell highlighting. Plus being able to move files up and down the list is useful for when doing the renumbering.
I think I'll hold off before telling Evgeny to take a different approach to his application.

My first suggestion would be to eliminate the entire options bar thing at the top. Or at least be able to have it dynamically change its information based on what you select. Right now he uses both that bar as well as a pop-up window (if you choose to do advanced/Winamp tags).
And then there are useful features and customizing abilities in MP3 Tag Studio that none of these programs have. It's a pain in the arse having all of them around (though by using Tag-It I just found out that MP3TS was responsible for destroying my "of #" tags in most of my collection (that's why this info didn't appear in emplode).
Hmm.. Might be a good idea to get some sleep. Been working like a SOB most of the day.
Bruno