I don't know how much lighter it is.... the Selle Anatomica is less beefy (literally I s'pose!!) than the Brooks. It also has a cut out to compensate a bit for a more forward position.
But it is essentailly a Brooks that is slimmer and has a cut out.
I think it looks flimsy on a hybrid where a Brooks would look better...so maybe there's a clue.
He has a 30 day guarantee. Check it out:
http://www.selleanatomica.com/
Be sure to watch this film, which I think is a riot...turn the sound on...
http://www.selleanatomica.com/Aug%20...ls%20short.mpg
Look at this fancy new one...ha!