If you were ever fortunate enough to take Joe's class at PSU, he taught the 3-hackle method. If I recall correctly, he highlighted the fact that this fly floated better. As mentioned above, he also claimed that it added some degree of life to the fly.
To walk down memory lane, PSU was on the term system as opposed to the semester system. If you had the class during Spring term, the class met in REC Hall until the weather warmed up. We casted and tied flies until such a time when the weather was good them we went fishing.
Good TImes!