I love the soft, stretchy material.  A million times better and more breathable than cotton, and not overly tight.  After a few minutes I forgot what I was wearing, which in my opinion is a good compliment for this product.  Just right for casual or work attire to keep your body sweat to a minimum.  I suppose you could wear them for workouts just as well, but I just haven't used them that way yet, so I can't accurately review them in that respect.  I also cannot comment on their durability, but I would imagine they hold up longer than cotton underwear, which seem designed to get holes in them after several weeks of wear and washing.