I lifted this video from the Fist of the Red Rebel site as a primo example of why ma-ai is a good idea. You simply can't afford to stand around within reach of guys like this, and when you get down to it, you can't ever tell if the guy in front of you has this kind of skill. This is why you'd better be moving as the bad guy first begins to move into ma-ai and you'd better be continually working to move away or behind him, keep him offbalance, and do not stop moving to do a technique to him. My recent matra applies here:
Do not engage. Refuse to engage. Roll the ball, brush off, and disengage.