These are among the ultimate in legwear.  The feel and comfort is incredible.  The fabric breaths, but still keeps the legs snug.  The primary consideration is leg shape.  For legs as good as  those shown in the picture, these are ideal.  The socks stay up w/o any problem at all.  I'd have some misgivings about legs that don't come close to those shown.  Slight thinner should be fine, but only to a point.  Significantly larger could be a problem.  I don't know that the fabric is meant to stretch a whole lot and am not sure they would stay up.  Moral of the story - if you've got great legs and want something that will flatter them no end and be as comfortable as you would ever want, these are for you.