outside of being notchy when cold, my MT82 is a dream. and im on the stock shifter,bracket, fluid.
i have a barton bracket, and plan on swapping to AMS MTG to get rid of the cold notchiness.
It is a two fold problem. First it's the GT clutch at high rpm. It was never designed for that high RPM shifting. The pressure plate is a little weak when compared to the Boss PP or any good aftermarket single disk. Second is the remote shifter. As the engine torques at high rpm(think momentum not torque) the gates become somewhat of a moving target. You can help eliminate this by new motor mounts or torque limiters. The clutch line, dot 4 fluid and shifter bracket(which I have done) all help but don't eliminate the root of the causes IMO.