I have the Ritchey SuperLogic Carbon one-bolt seatpost on one of my bikes. The post is super light (138gm in 27.2 x 300) and the clamp has held like a champ. I have experienced zero squeaking or creaking of any type. Note that when I installed this post, I used the Ritchey liquid torque to it to increase friction and reduce the chances of it slipping. I am very happy with this post.

FWIW, I also have a Ritchy WCS Carbon one-bolt post on another bike and I have been equally pleased with it. The only real difference is that the WCS is a bit heavier than the SuperLogic and my WCS have woven carbon finish while the SuperLogic has a UD carbon finish.

Also, the weight of either the SuperLogic or the WCS can be reduced by an additional 7gm by replacing the steel clamp bolt with a titanium clamp bolt.