Just received the Arenberg bib tights. Figured I might have to send them back since I had already done so with another brand of bib tights. Tough to get the fit right when ordering online. But was very surprised. Fit was fantastic and they feel great. No extra bulk in the seat. Material seems to wrap you well and is very soft, not abrasive. I am 5' 10" and weigh 175# with 32" inseam and 34" waist. The size Large is a great fit.
Can't say how they are on the bike, because little too warm (90s) to wear them. (Summer sale price too good pass up.) They don't feel like they will be the best windstoppers, but I think they will be warm.