More Navajo plying

Did some more spinning using the "Navajo plying on the fly" technique.  Today I tried it with my Turkish spindle and one other low whorl spindle.  It is doable but this method definitely seems to work better (i.e. it is faster, at least for me) with a top whorl.  As a comparison tonight I Navajo plied in the usual way the alpaca/bfl/romney singles I recently finished spinning.  I suspect that while plying as you spin is pretty cool it might be just that - pretty cool but not really faster or more efficient.  I need to play around with it some more before I make up my mind for sure.