I just got my MJ Waffle and I gotta say, I'm amazed. A lot of technical clothing feels really artificial, and compromises comfort for strength.
Somehow, Matix managed to create a technical shirt that feels really organic, and REALLY comfy. For 30-32 inch waist, even if you have broad shoulders, get the M. It fits perfectly.
I daresay this is the most awesome shirt I've ever had the privilege of wearing, and I'm immediately ordering two more.