7B Thrusters is lot of weight for no reason, stick to 7D's. Even the 7A thrusters only provide a minor improvement. If FA-OFF didn't exist I wouldn't fly the T9, when engaging flight assist it feels like dragging the ship through a thick atmosphere, I only engage FA when cruising level over the surface of a planet, like an autopilot.
In supercruise all the ships perform as if they have max thruster ability, the T9 performs as if it has & 7A's, not a huge improvement, blue zone steering in SC is important.
In normal space you have to use FA-OFF to get the best out of it, use all thrusters. In a turn - I decelerate into the blue zone whilst applying full yaw through my pedals, roll into the direction of the turn and apply pitch to pull me through the turn, it makes a huge difference when done correctly. Same deal when flying the Cutter.
Bottom line - The T9 is Heavy, extremely unforgiving and requires a very focused flying method to get the best out of it, hence why many hate it with a passion & a few absolutely love it.