China cycling on YT released a video on it. Very low stack, very stiff, very uncomfortable. A lot of that absence of comfort is probably due to that blade looking seat post. It's ironic, because you want a seat post to be stiff laterally, so it doesnt bend when you pedal seated, side to side, but you do want it to bend / absorb front to back when you hit any road imperfection. So, mechanically, you'd actually want the blade shape to be turned 90 degrees, but because of aero, you dont. Which, btw, is probably the biggest ad for a round seatpost.
There's no mention of wind tunnel testing, so they're selling an aero 2k frame w/o aero data.
For most people in the west, ie anyone who isn't only interested in a very aggressive, very low race bike for race day, that's probably a poor frame choice, especially if you're tall.
Joe mentions the supersix evo hi mod rim as peak stiff and peak discomfort. I rebuilt mine (the himod version Sagan raced before going to specialized) and rode it a few times this summer after doing thousands of km on my LT268. Yes, it feels nice uphill, although it's not faster than my LT (as per strava, doing hard efforts on a climb i know well), but man, anywhere else, it suuuuucks. I have 25mm high end tubulars on bora one 50mm wheels. It's jittery, uncomfortable, sketchy downhill because it doesnt feel planted at all, it's slow AF on the flat, plain horrible in comparison.
My supersix weighs ~6kg, and the 268 is ~7.5.