I like Mavic Cosmic bibs so much that I just ordered another (in blue so I can distinguish from the two I already bought):

Mavic Cosmic Bib Shorts Eclipse/White | The Pro's Closet (theproscloset.com)

The shoulder straps are wider and thicker and provide a firmer and more elastic tug to keep the bibs in place. (If you are significantly above average height I imagine they can give you a slight wedgie.)

Now I understand why some reviewers state that the Gore C5 bibs (which have semi-sheer shoulder straps) feel cheap.