So you never tried using all the same style prop? All E or all SF. I've gone back and looked through some of the stuff I read earlier about using different size/pitch props top/bottom, and I found several setups that people liked, none of which used different style props. Not saying it wasn't worth a try...
Also, when you leveled your motors, did you level _both_ motors on each arm? With the round tubes and clamps, if the clamps aren't tightened evenly, the motor plates also won't be parallel. It was a bloody hassle getting both motors to be parallel and even... 3 times! And of course one set got knocked out of alignment when I dorked the prop...
I did a quick test earlier this evening with 11x5 top props, all CW, and 11x7 bottoms, all CCW ("old" mix). I picked up some new vibrations from switching props (balanced, yes), so it was just a quick flight before dinner. The yaw is very balanced though, as are the motor outputs. Log graphs look basically like 2nd flight, above. Not sure if the vibes are from a bad prop, or if the combo of different pitches causes the extra vibrations (which I see in the X & Y accels, not in the Z).
I will try a 12x6 top and 11x7 bottom next, after I find the vibe source. Besides looking for yaw imbalance and checking motor temps, I'm not really sure how to quantify these prop tests.
-Max