This is a comfortable and cozy slipper.  Yes, arriving at the correct size could be a challenge, but when you find your size and wear the slipper for a few days, it conforms to your foot and feels wonderful.  I have a narrow foot, so size can be a problem.  This particular style seems to be more conforming and forgiving than some of their other styles.  It comes up higher on the top of the foot, so it tends to slip on the heal less.  I doubt this would be a problem  for those who have a wider foot.