I have the bibs as well and yes you stay dry. The down side is that most bibs do not have a relief zipper.
This actually limits the amount I wear them. As taking off the pfd, skirt and dry top just to relieve myself is a true hassle.
I do plan on sending them in to kokatat to have a zipper installed.
"We should restore the practice of dueling. It might improve manners around here" -Edward Abbey