For those who have not tried synthetic fabrics for underwear, this is the best of those available.  Unlike some synthetics, it breathes well, has minimal clinging, and has antibacterial properties.  This latter is a must for a synthetic as they smell terrible without this feature.  They dry fast and and I still have the first pairs I bought from 5 years ago.  The elastic has held up well in the waistband.  These have an open fly unlike many of this genre.  They are great if you are trying to pack very light as they can be washed quickly and dry overnight easily.  Nothing beats cotton unless of course you are going to get wet.  Try cotton underwear with a polyester golf shirt and polyester pants where everything wicks the water straight to your cotton underwear.  You look like you wet your pants and you feel miserable.  These are perfect for that situation, just don't wear cotton socks or the problem will be in your feet!  Also great if playing in the rain when you end up sitting on a wet seat.