Thanks for posting this. I have not gotten the chance to try out the new PA4. Michelin has had a great track record lately with their new tires: PS2 -> PSS was a big upgrade, and they did a great job with a couple other new releases that don't really come in M3 sizes.
Keep us posted on how these do when the snow starts flying.
I have accepted a new position at Tire Rack and am no longer in the sales department. firstname.lastname@example.org
is available to assist with M3 questions.