I have 2 of these posts on bikes. And more idle in bins. This is a mid-80's replacement for Campy's outstanding 2-bolt offset design from the 70's. The earlier posts were a pain to set up, but once you did, they were bulletproof.

The later one-bolt design had two major flaws. First it used an easily-stripped 13mm hex head bolt to tighten. You going to carry one of these wrenches around in your seat bag?

Second, this post always loosened up - eventually. I have personal experience here, in that I was stranded 30 miles into a wet ride with a seat facing downwards at a 30 degree angle after the clamp assembly slipped. You could forstall the inevitable by liberally coating the bolt with green Loctite, and torquing on the bolt until your eyes bugged out, but these posts will still eventually loosen up.