Power to weight for ducted fans was always to try and get as close to 1:1 as possible... less meant loss of performance in some manoeuvres especially the vertical. Having said that, I've seen Avonds Eagles weighing 15/16lbs leap off the deck with an OS91/Ramtec pumping out 12lbs static. How long's your strip Dave?

Just one small observation.... your photo shows the models sitting a bit "nose down", that won't help rotation

Cheers
Scott