I have been using BIAB since the beginning, the early DOS versions, and really like it.
Yes, I am surprised that in 2011, the basic UI has not changed since the very first Windows version (made for Windows 3.1.) (Even the fact that it is by default installed in the root directory (rather than in Program Files), and doesn't use the registry. Those are not important at all to me, but just another indication that BIAB remains with its very first Win 3.1 setup, did not ever even adopt the changes of Win 95.)
It might be wise to spend some time and energy, not just in adding more and more similar pop and country RealTracks, but in trying to make some fundamental long-overdue changes to the app.
Not only in UI, but also in functionality. For instance, I am amazed that still, after all these years, and so many user requests for it, that chords cannot be changed at more than one per beat! When will that major limitation be fixed?