I purchased the size medium, and they fit nicely on me (I am a size 34 waist)  They are snug, and remain snug all day, which is kind of what I was looking for.  The waistband also seems superior to Hanes and Fruit of the Loom boxer briefs, in that it has a broader and more reinforced band of elastic, but these are a tad more expensive than those.  The fabric is soft, and not at all itchy.

These don't have a fly, so if that bothers you you should avoid them.  I never use the fly anyway, so this doesn't bother me at all.