Just received the saddle today via FedEx. Sticker price is ¥699 (~US$105) without shipping and handling, so maybe expect it to retail at that price.

Measurements on the tag were accurate (275mm x 145mm), with the sticker on the packaging stating a 275x150.

Weighs slightly less on my kitchen scale than the 270g advertised.

Looks like they will be coming out with carbon and titanium rail versions.

Smacking this on today and testing it out.

*EDIT*
Post-ride

Did a couple of two hour rides in two different bibs (Rapha and Monton).
I have only tested the Specialized Romin Evo at a shop for 15 mins so I cannot make any direct comparisons.
I can however compare to my previous Chiner Selle Italia saddle that I've ridden for ~2000km.

Pros:
I realise that comfort is supposed to come from the bib padding and not saddle padding but I really did feel a difference in both comfort and support.
I was adjusting my position less and didn't get any numbness in my ass. I felt planted, and even in different positions, my sit bones were well supported.

Cons:
Mud and gunk got trapped in the holes and required some slightly higher pressure washing.
Weight can definitely be a turn off, but I should be the one shedding weight 

Mind you, I'm an unfit 91kg rider mostly cycling on a smart trainer, but I'm a convert. Will definitely be ordering the titanium rail version in the future for my brother as a christmas gift (and maybe one for myself).
It's a fifth of the price of a branded 3d saddle for my region, and gives a much better value for my money.

There's some discussion and links on road carbon saddles this thread if any of it interests you. https://chinertown.com/index.php/topic,3250.15.html

Found this new company called Cosy Saddle

They're making this 3D printed saddle


Looks much better executed than the ZTTO. According to this video, they're also developing carbon and short nose versions.

Just ordered one piece out of curiosity. The weight doesn't bother me much if there is comfort to be found! They also told me that the carbon rail version will be ready for sale by the end of this month. If I like the current one enough I'll probably order the carbon rail version as well.

What is the width of the chainstays at the rear flat mount points? I may have to give this frame a try too.

Is this where you mean? I can take a more accurate measurement tomorrow if this is not sufficient.

Lovely frame.

Can you say more about how the Carbonda headset for the integrated bar is inferior to FSA's? I'm buying FAS's stem and have no objection to buying their headset. I could wait till after the frame with headset arrives to decide about ordering the FSA headset, but I'm very curious.

In order to have the expander flush with the top of the handlebar, you would need to have an offset of about 3mm due to the thickness of the part that sits on top of the fork and stops the expander from dropping straight in. In the image below, the top half is the FSA ACR expander, and the bottom half is the one Carbonda ships with the bike, which you can find on aliexpress. Both headsets were tightened to a semi-snug fit (expanded, but still able to rotate freely) so show where they would approximately sit within the steerer tube.

The FSA ACR expander covers a good region of where the stem bolts are. The Carbonda one barely covers half of the top bolt. Note that the expander cannot sit any higher. Although you can have the stem sit slightly lower, the length of the knurled region that pushes against the steerer tube is just about enough to cover the space between the two bolts and would need some fiddling to get right.

Also the knurling on the FSA ACR expander definitely feels like it has much more grip. When tightening both to a semi snug fit, I had a harder time extracting the FSA ACR expander.

The bearings I got from FSA also ran smoother. As for spacers, FSA spacers were out of stock, but I know they can be put together without removing any cables as they join at the space where the cables route (like a padlock), whereas the Carbonda ones join together at the gap for the steerer tube, with the gap for cables fixed.

I am aware that carbon tubes are strong when there are equal directional forces and that the Carbonda/AliExpress headset is sufficient for 99% use case, but I believe that the additional expense for a FSA headset is justified by having peace of mind.

Also, you cannot use the routing on the FSA ACR expander that was intended for the front brakes as it seems that Carbonda has routed the front brake hose to have a single entry single exit channel (from the flat mounts to a couple of inches above the crown race). If I try to push a routing cable from the top of the steerer tube, I couldn't get it to exit at the fork disc brake exit hole, though this could be ineptitude on my part. This doesn't bother me much as I'm okay with using the designed method of all four cables going down the same headset gap, but may be an annoyance to some.

In any case, Carbonda are pretty happy to accommodate to small customisations, and if someone were to want to definitely use the FSA ACR style routing, you could probably request for no channeling on the front brake hose.

Just received my shipment after being given a tracking number on Tuesday. The box looks in good condition and I can't wait to open it once I'm off work.

Would an adaptor like https://www.ebay.co.uk/itm/292873071470 work? To be clear I have never ordered from this source, it was just the first relevant search result.

Today I've been fighting with the cable installation for the front derailleur. I guess htey have mostly 1x front or electronic gear in mind; it was a mess to get the cable into the bottom bracket guide. It is simply too tight: when the guide is insterted into the frame there is not enough space to slip the cable w. end cap into it. Slipping it into the guide when it is removed it is nearly impossible to put the guide back into the frame. Iwanted to install a liner to such a end cap like Aesch has posted but no chance. Had to cut and drill (I hate that at a new frame) and now I have the outer cable/end cap more or less clamped between the guide and the frame and a separate piece of liner from the guide up to the derailleur. Don't want to touch this soon again...
Also the gap between fork crown and frame is too tight; when preloading the headset it starts to rub, causing stick/slip. Have put a flat crown race fram another headset plus the FSA crown race; still a very small gap but no rubbing anymore.
Oh goog old times with cables outside and standard headsets!
When the kids are sleeping I move on...

Thank you for the detailed description Michi. If it's convenient could you maybe snap some pictures? Particularly of your solution to the bottom bracket guide. Thanks in advance.

Ordered August 8th, size M. Katie sent me pictures of the painted frame:

That's a really good color. Matte olive? Can I know what parts you'll be putting on it?