Here is a recent study looking at US pediatricians and their compliance rates with ACIP recommendations up until 2009. http://www.scirp.org/journal/PaperDownload.aspx?DOI=10.4236/ojped.2012.23036 The full paper is available.
An average of 94% follow the guidelines. It's higher for individual vaccines as you can see in the table below.
A more interesting question was asked: would you follow the recommendations for future children? And compliance was lower. Only about 87% said the would follow all the recommendations. The biggest ones were: postponing MMR until after 18 months and skipping rotavirus. The article also outlines the thought process behind this and the types of pediatricians that would tend to make these decisions.
This is also a self-selected survey. They are all AAP members.