I agree with you that a ti post feels smoother and less harsh (than Al), with just the tiniest bit of sway only noticeable under massive g-forces.
I probably wouldn't have picked the Campy post if I was building my bike up, because there are so many other choices, but it came on the bike and I see no reason to replace it, 'cause I likes' it.
USE just redesigned its post, with a better bolt design because their small bolts were stripping a lot. It is probably one of the lightest out there, although I'd have to check http://www.weightweenies.starbike.com/ to be sure.