The gray uniformity of the M series is an improvement over the E Series. You can no longer see the individual LEDs behind the LCD layer. However, narrow darker bands create a dirty screen effect on panning shots.
The motion blur is average-good for an LED. Contrary to the E series, the 'Motion Blur Reduction' feature does not reduce the blur (see the Q&A section for details).
The remote is more advanced than the one available on the E Series. There is a full QWERTY keyboard on the back of the remote.