I use one, and a "whaletail" on the back during winter, on the single speed. On our regular night rides it is amazing the difference between those who are "too cool" to use a crud catcher and rear mudguard and those that don't care how cool their bike looks, they would rather be allowed into the pub after the ride!
My Genesis even has bosses for a crud catcher - quite a few of the British designed bikes do: Orange, Genesis, etc.