I bought these because I was getting varicose veins and my doctor told me to wear support hose when I would be standing a lot. I've worn them a few times so far. They are SO hard to get on, but are pretty comfy once you get them on. I thought that the waist would constrict my tummy, but they are just as comfortable as maternity pants.
I was in between medium and large on the size chart (5'4" and 138 before getting pregnant) so I went up a size. I'm glad I did. They fit great.
My advice: wear exam gloves when you put them on. I picked up a pair when I was in for a doctor's visit. They keep the hose from getting a run from your fingernails while you're putting them on.