Canyon came up with VCLS seat post to soften the ride on harsh roads. Chinese carbon fiber manufacturers have been quick to copy the concept. The idea is great and the posts look great. The downside is that under a fat bloke (86-92kg) like me the seat post has the tendency to slip and tilt the saddle. The situation can be handled only with generous application of carbon paste and quite a bit of torque. The problem is of course that you would not really like to crack the fragile carbon by over-tightening the clamp bolt.
I had 27.2mm for RT-90 and now 31.6mm for Pickenflick. The delivery from Aliexpress took couple of weeks and posts were well packed. Markings printed on the chinese copies are useless, but so far the posts have held up well on normal road use and 6Nm has kept the slipping at bay. Overall I’ve been happy with the posts. However I might get another type of seat pin for cyclocross where there much more rocking back and forth and the slippage is really annoying.