In the ongoing saga on this subject, I know several of our "experienced builder/members who work in the trade" forum members have definite opinions on the superiority of plywood over OSB.
Today, I received an article from BuildingScience.com where for the first time (if memory serves) the people at BSC also state that plywood is in fact better than OSB. Their main reason stated was that plywood dries much better after getting wet, and that with all the techniques and materials we use today to build houses that we need all the help we can get in the drying area.
While the article is about stucco, much of the basic information in the article applies to all claddings. And it also discusses the importance of "ventilated cladding." In case anyone is interested, here is the article.
http://www.buildingscience.com/documents/insights/bsi-029-stucco-woes-the-perfect-storm (http://www.buildingscience.com/documents/insights/bsi-029-stucco-woes-the-perfect-storm)