Yeah those HK motor are not vey efficient for sure.
I getting right at 10 1/2 minutes on mine which is plenty for me I usually start to get board with it after about 7-8 minutes.
After a 10-10.5 minute flight my voltage per cell is usually at about 3.72- 3.78v per cell , I'll have to check on the charger the next time and see how much it puts back in.
On my Tarot ZYX on mine I have my deadband set at 10 default is 60 and yes the lower deadband give it a much better feel.
I don't have a cyclic response so to speak I have "Acceleration" and "Roll & Pitch Agility" and you can crank those 2 things up to where it is like trying to balance a nat on the ponit of a needle without sticking him.
The tail gyro on the Tarot is pretty killer as well I have mine cranked up on the gain and slowed down on the "pirouette speed" so it is more scale like , never have seen a real 1:1 heli doing super fast piros.
Crazhorse IIRC I think I cut off about 3/8's of an inch off a 24" piece but measure with your belt installed on the heli like I did to be sure.
I put the AH-1W 450 Cobra in the dirt today and it finally did the old girl in I think , so I'm thinking of a new project for her.
I've threw the fuse in the trash and I'm thinkin' a stretched 450 to a 500 class to fit in a 500 size fuselage .
As soon as I figure out how to bolt a 500 head on a 450 shaft I'm in.