I probably have one of the first assemblies on this frame; I've driven about 300 km in total, so I'll share my first impressions.
Pros: visually, the frame looked very high‑quality, all the mounting points were even, everything assembled perfectly, the clearances were excellent, and I had fun putting in wheels with 40 mm tires.
It rides well. I haven't had a chance to really push it yet, but during short training sessions it behaved very nicely; the bottom bracket is stiff.
I'd also like to note how well it handles due to the smaller steering angle and fork offset, unlike most aerodynamic competitors. It rides smoothly and steadily even in strong winds.
Cons: the 300mm seatpost might be too short for some people. I took the L size for a height of 187cm, even though the manufacturer recommends XL for this height, but it seemed too big to me. And my seatpost is set at 2.5 out of 10, at a height of 77cm.
The stock handlebar is quite heavy: 390g.
The frame itself isn't light either: 1130g. For an aero-bike, this is a normal weight, but compared to the 940g listed on the website, the difference of 200g is quite significant, despite the sizing and painting.
And there's a small downside regarding the package — nothing is included in the package except for what's necessary. They could at least have included their own bike-computer holder.
Bikecheck:
Frameset - Mentech ARC Sport, L-size
Groupset - Sram Rival E1 rear derailleur, Sram Rival D1 levers&brakes, Sram Force E1 cassette, KMC Flattop chain
Crankset - Rotor Aldhu cranks, Magene P505 powermeter, Pass Quest 50T chainring
Wheels - Next, 55mm rear, 45mm front
Tires - Conti GP TR 30mm
Final weight: 8kg.