Came to the conclusion after much pondering there's no such thing as a cosy saddle. Sitting on a bike for 3 hours or more is a totally unatural pastime. Whatever saddle used you're going to become fatigued because of the concentration of a lot of weight in a relatively small, hard area.
Loads of people blame their saddles for their arse feeling sore when all along it was their fault through lack of good hygiene.
Make sure your shorts are washed before and after every use so bacteria can't get to work on your nether regions.
I also use vaseline. Lubricates, reduces sweat which causes sores.