The inherent advantage to 3/9 is one can see both ends of the blades....thus the liklihood of missing a tiedown left hanging is decreased as opposed to either the 2/7 or 2/8 method. Also...if you cannot see the blade turning by the stated RPM using any position for start you have more problems than blade tie downs. Also...if you recall...I said one should visually account for that tie down......and never...never leave the tie down hanging from a blade.
I can assure you...when the accident chain starts with the 2/7 or 2/8 position...it will also include a tiedown left hanging on the out of sight blade.....and as you glance at the now turning blade what will immediately catch your attention is the now visible tie down swinging well out to nicely accomodate snagging the faster turning tail rotor.
Manually turning the blade a bit also allows one to listen for any unusual noises...which is not a bad thing either.
212man....I cannot wait for you to start flying real helicopters with many blades....you will have to start wearing sandals to be able to keep track of all those numbers. Is that Gulder working on you today by chance? Not that you would be inclined to be celebrating your pending parole.