MC6s work better in Poser, but I'm not sure if D|S will accept them. You could always provide PZ2 style MAT poses for D|S users.

You also need Poser 6 or later to use MC6s, so you are cutting off a (probably small) part of your potential Poser-using audience. I tend to assume that people who are still persisting with older versions have enough know-how to apply materials by hand, anyway. ;)