I like the bowline with the Gri-Gri. After spending a half day working rescues off of the various climbing systems, the Gri-Gri seemed easiest. But if you were planning a long rap off the spar on a job in which you had room to drop a big pole, then the AFS is great.
That said, this was my first rescue course, I'm sure Burnham has more experience with the various systems and rescue methods.