Namaste Ananda,
On the plus side, the well-thought-through sequencing of asanas (enhancing each other in a chain) certainly speeds up one's progress.
On the down side, most Astanga Vinyasa teachers are obsessed by asana at the expense of pranayama, full-fledged bandha, cleansing kriya, mudra and meditation. With some students, it also seems unsafe to postpone technically challenging asanas such as inversions until the Finishing series at the very end of the lesson when their muscles are exhausted and short of water.
Astanga Vinyasa in the West lacks the 40 - 60 years' tradition of practice found in some other flavors of yoga here; that results in too many inexperienced, recently-graduated, not too confident teachers who follow the series quite slavishly, but IMHO it makes more sense to make yoga an individual practice. Therefore, I try to attend astanga wokshops by teachers who have practiced yoga for several decades and who have a wider frame of reference (not astanga only). I agree on sequencing but disagree on one size fits all, no point in being pushed by force into lotus before being "allowed" to do arm balances, or vice versa :-)
