The normal ear pads that comes out-of-the-box feels ok to me. I used my M100 thrice already on two and a half hour gigs since last Tuesday, and will be using it again tonight. So far, they feel great compared to my old Sennheiser HD280 Pro. My ear size is quite normal and I don't have the need for the XL pads.
Does the XL pads make a sound difference with the standard ones?