You're running Green Cube? Did you have to mess with PID's? I have MAS 10" and 11" but I find the 11" MAS to fly pretty poorly, especially in windy conditions (also Green Cube on mine). Maybe I should try the APC but so many props already.
I installed the Green Cube in Solo # 2, my Solo #1(with the 11" props) still has the stock Pixhawk. The larger props work fine with the stock pids; they do have a gyroscopic effect I find helps smooth out the flight path. Remember I am doing Follow with these props so I want smooth graceful movements. Early on I used MP to for tuning but I found it wasn'r necessary as long as I keep the movements smooth. I do find with the 10" props Solo whips around a bit more.
Also I turn down the sliders for performance if the sticks are too responsive Solo will jerk around with stick inputs.
This is normally how I fly but the 11" was being really jerky so went back to 10". This is with Green Cube and sliders about half way. Would like to get 11" working properly for slight battery life increase.