for the 90
690 or 710, 3D tend to go for the 690 as they are slighly harder to bog and give faster cyclic response, 710 should give slightly more pull in clime out and slightly better auto.
To be honest iv found very little diffrence! I can't tell the auto diffrence between the 2, I will say that I like the 690 for 3D more because they do tend to perform the fast pitch moves like the tic toc and nife edge easyer. (or atleast for my happy pitch fingers!)
for the 70
Im not to sure, I should think 680 or 690 should be ok
Im personaly flying the BBT Blades at the moment and love them, I used to fly SAB but not sure im going to go back now!
(Quick UK Pilot) :- What can I do rather than What Can't I Do! :)