This Gilt sale was my first experience with BoO and I got a size small in a l/s OCBD and medium in the s/s contrast collar and I think the fit is almost identical. Based on this one time I would say the s/s tend to fit a tad more snug that the l/s in the A fit. I'll post my pics in a bit. That's about right with my experience, the S/S (I wear a L in BoO A Body) is noticeably more snug then the L/S. And even in the L/S the overdyed BD's is definitely a bit tighter all around then the regular BD's.