This is my third order of these, so I now own nine pair.  I find they fit well and are very comfortable, especially for vigorous activities.  I have a 37-38 inch waist, large size.  I like them when I workout and bicycle, since unlike cotton, they do not retain moisture.  But I also use them for everyday wear.  They dry quickly, which makes them good for longer trips where you have to do some wash.

I can't comment on how well they last long-term, but I have been using some for over six months and they are standing up well so far.  Estimate that is about 15 to 20 washes on the oldest three.  I air dry them.  I am concerned that anything except really low heat in the drying, for a short time, will damage them.  I put them on a drying rack and, unless it is very humid, they dry overnight.