Here's a link that may not answer your question, but it has some good info:
http://www.woodworkerssource.com/blog/?p=3066.
I think Baltic birch is used a lot because of availability. It has some good qualities and is relatively inexpensive compared to cherry, maple, and others. The quality varies quite a bit by where you get it and how much you pay. The big box stores sell construction/cabinet grade Baltic birch plywood which tend to have voids. The edges of these boards are usually covered. In scrolling, you want to avoid voids as it weakens delicate pieces. You can get aircraft grade Baltic birch plywood as certified and uncertified. You will pay more for the certified plywood but there seems to be no difference in the quality of the two.
I use it on most of my projects because I don't like a lot of grain. It's just my preference. I also use 1/8" plywood and it's difficult to find a variety of species at that thickness.