Lise, I have a Serfas Carma http://www.serfas.com/performance_saddles/WCST-1.shtml on my tandem and so far have been very happy (I can't move around as much on the tandem, so seat comfort is a big deal - and I've had about 20 different saddles on it in the last year and this is the first saddle that has let me last more than 30 miles).

I have a Serfas Tri-W on my daily commuter http://www.serfas.com/performance_saddles/TRI-W.shtml and it's OK, very long and narrow. I'm thinking about getting a second Carma - recommended by my PT - for the daily driver!