I did AlmerÃa to Faro (600kms/ 7hrs) a couple of years back on my 30 yr old 3vd and not once did I get off the bike with a sore bum. Maybe it's more bone and bum shape that determines how comfortable a seat is,rather like touring screens. What works for one, doesn't work for others. Sheep skin does help a bit but it gave me Betty Swollocks.