they're heavy and ugly and overpriced and archaic and made of nasty dried out skin.
OP, try the selle san marco rever k. i ride mine on my tark bike and love it. i've sit in it for 80 mile days with no problems. light, too.
feels good with or without chamois.
the rever (minus the k) is nice too, but a bit stiffer (slightly less padding). i own it, but haven't spent more than maybe twenty miles on it so can't really say how it goes for the long haul.
the most time i've spent on the rever k was a weekend doing the ms150; roughly 75 miles saturday, 75 miles the next day.
worked great.