Indeed, as a new user, I am really puzzled to see not much discussion about User Tracks. I believe they a very interesting and exciting feature and a strong selling point. I have the Audiophile version, so I have all the great RealTracks that PG Music provides, but even in my case I think UTs are very useful, because RTs obviously do not (and could not) cover all the possible styles / instruments / needs etc.

Even if I've had BIAB for just a few weeks, I already managed to create a few very useful UTs. I cannot post them here because I think (not really sure) I would violate the copyright of the VST instruments that I purchased and created the UT from. It's two ukulele strumming VST instruments, one is 8dio Ukulele Strummer, and the other one is Cinematique Instruments Ukulele Trio. Both very affordable (especially the Cinematique) and great to create UTs from. The UTs came out really, really good, and they are very useful, since right now we only have a couple of ukulele RT.
(in the Yahoo group I posted a detailed description of how I made them).

It's just an example of one of the (many) reasons why it should be fun and useful to discuss UTs.

A great, great help should also come from PG though, by fixing the current issues related to UTs (3/4 time signatures, shots and holds, transposing etc).
Please PG !!! :-)