"The Conquest sprung MTB model is probably lighter than a typicla sprung seatpost/plastic saddle combo and a lot more durable."
I would never use a typical sprung saddle on anything but maybe my wife's bike. I'm used to a 250g narrow crotch-chopper with a love channel. I had always thought the wide springy stuff was best left for the commuters.
Maybe I'm wrong. I think a B-17 could possibly be too wide...may need to check the B17n, swift, or team.