Somewhat related....This is a very interesting study done comparing and assessing IB vs AP. I found it in the Duke Gifted Letter, in the right navigation bar under "resources" on this page http://www.dukegiftedletter.com/articles/vol10no2_sh.html

Thomas B. Fordham Institute - Advanced Placement and International Baccalaureate: Do They Deserve Gold Star Status?

We have both IB and AP in our District. My daughter has attended a special self-contained GT program in elementary school. For middle school options, such GT program is replaced by two different GT/honors tracts, of which the IB MYP program is considered the more rigorous, therefore has more stringent acceptance criteria set by the District. IB is by no means "gifted ed" but, the District has positioned the program as targeted for those kids.