CF posts are not worth the money in my opinion. This magic 'vibration damping' just doesn't exist as far as my arse can tell - you're much better off having a seatpost that stays put, won't snap and more importantly....the more of it that sticks out of the frame, the more flexy it will be ergo, the more 'comfy' it will be.

The Al seatposts in the Peloton are because, yeah, easier to clamp with less finesse, and many teams run DA posts because they're sponsored by Shimano.

No point in going for lightweight if you have to add lead to the bike to get in into the UCI limit!

*sits patiently waiting for some monkey to PM me complaining about my new avatar*