I imagine the bevel is concave but to such a small degree it wouldn't really make a difference. Something probably measured in microns. Concave bevels in themselves may have some theoretical advantages in certain cutting tasks. Whether shaving hair is one of them I don't think anyone could say for sure.

As far as my own personal preference goes, I moved more towards the French/Continental tradition of relatively long times between honing and judicious use of the pasted strop because to me the convexing of the edge gives the best shave.