Examining the "M" Effect
The problem TaylorMade are trying to solve

Hit a tee shot with a swing path that is out-to-in with an open face at impact and the golf ball ought to go a long way
right (right-handers) but, if you strike it towards the toe, then the ball can go left with a draw or even wild hook. 
How does that happen?

Strike the ball towards the toe, and the clubhead will rotate to the right at impact.
That will not only lose you ball speed but also (represented by two gears in the image above) 
as the toe of the face moves right, impart right to left side spin on the ball.

That's why Drivers were designed with
quite a considerable horizontal bulge.
The idea was to try and design an
"accurate" Draw into the ball flight
so that it landed in the Fairway.

As faces have become thinner, it has become more difficult to design in the correct "gear effect."

And so we have Twist Face from TaylorMade.

A design solution that means we no longer need "Bulge and Roll", and we can get the ball onto the Fairway more often,
despite miss-hits towards the Toe or Heel.

That's the theory behind this innovation.
So, why not come and let's see how much impact it can make on your Tee Shot performance.