I bought a Brooks Swift on the basis that people rave about the comfort factor, but also because I liked the looks and tradition.
After my initial excitement at 'buying a new piece of kit', I rationalised and thought back to some advice I was once given by an elderly cyclist - namely, that even with the most comfortable saddle, your rear will hurt once your legs have become too tired to support your weight properly (yes, he did mean support your weight while seated).
I tried it on both my Tommasini and Pinarello and think it looks just plain wrong. Maybe on a sturdy tourer, a stylish fixie, or a 3-speed English bike, but otherwise I think Brooks are a very successfully marketed anachronism.