Yeah tweaking hell is real, it's hard to work out the optimal setup without going through a whole lot of cable management nonsense - and then for it to not be what you thought or slow and uncomfortable due to something you hadn't considered.

A friend said the same about raising the stack and initially it had me thinking.  Certainly it seems popular and fast for TT/Tri bikes.  Then I realised the difference - the contact point on a TT bike is the elbows, whereas on the road bike it's the wrists.  Angling the extensions up on a TT bike doesn't change the angle of your back because your contact point (elbows) stay where they are; on the road bike a raised stem pulls everything up including your shoulders and head.  Also on a TT bike the torso position is likely pretty good already, the marginal gains from stack height are more about getting the shoulders in and forearms hidden in front of the chest.  On the road bike, most of the benefits are still coming from the lower shoulder and head height / flatter back.

My plan is to take the bike / geometry to a bike fitter and get them to replicate it, and also take the 2 bars I plan to try with me.  They can then tweak stem length and angle until with my hands on the hoods and wrists on the bar, my upper arms are vertical, forearms horizontal and back as flat as possible.

Hopefully (fingers crossed) what we work out during the fitting will perfectly match the position once the new cockpit is on the actual bike.

Hi Tobi, I use a Cateye Orb on the rear. The rubber stretches enough to fit just fine even with the monster seatpost.  Unfortunately, no such luck on the front - I need to find a suitable small day light which can clip to the GoPro style mount under the computer.

I would not expect it to be comfortable, and the stack is very low. I would run the widest tyres the frame can take as a starting point, and I think the bike can be fast IF you fit on it. That's a huge if. The geometry is extremely aggressive and doesn't fit most.
The worst bike you can buy is a harsh frame that doesn't even fit you.
I say this as someone who bought harsh frames that didn't fit me ..

As pistonbroke already said and perhaps counterintuitively, it's not a harsh ride at all.  Subjectively, more dampening than the TCR I migrated from.  If anything my concern is that it's slow because it's dampening too much, but I need a lot more miles, preferably not in Winter and also some experimentation with tyre pressures, to confirm.

It's also very comfortable *for me* but you're quite right it may not fit most or even many.

Doh!
Look forward to seeing them

I can barely remember the good weather :'( The amount of rain is crazy at the moment.

Tell me about it, it's been desperate.  I was going to keep this bike for the good weather and get the old one off the turbo for the Winter, but what's the point of having a nice bike for 3 weeks of the year? Instead I invested in some good wet weather gear, and make sure to give it a good wash after every ride.  When you feel prepared for the weather, it's fine once you get going.

NGL though, I'm looking forward to those warm Summer evening rides 

Better late than never, I have the bike built, dialled in and have had it out for a couple of rides - one group one solo.  Looking great, apart from the wheels - I have some Light Bicycle Turbo Pro 78s on the way.

Build
According to my mechanic, the build wasn't too bad just a few niggles:
Internal cable routing was tight as a gnat's snatch. He reckons it wasn't really designed for mechanical transmission even though I specifically asked Chris prior to ordering.  See the photos, he's done a great job and it looks very neat, no issues with steering but he said to be careful over rotating it e.g. when putting it in the car etc.

On the rear stay there is no hose lug (if that's the word - the bit inside the exit hole which stops the cable sheath slipping into the hole) so he had to fudge it.  Works fine though.

I also had seatpost slippage issues despite the grip coating, but tightening it to 'hope I don't break this' Nm sorted it fine.

No issues with RD clearence etc, shifts smoothly through the full range of 24 gears.

Ride
Overall lovely.  I'm not a peak power guy, but no obvious flex. Some of the roads near me are God-awful, and it's noticeable smoother over them than the TCR was.  It had alloy bars, I don't know if that contributes.

Geometry is a big improvement - getting the seat forward, shorter cranks and higher seatpost due to that, results in improved power output for the perceived effort.  It's also very comfy being more forward in position - there is more weight on the hands certainly but puppy-hoods and drops are both nice to ride.

I have a fairly flat 30km loop I do for testing.  The plan was to ride it at the same power as previous efforts and see a small but significant increase in average speed.  However, firstly I forgot to re-calibrate my pedals for the short cranks so reported power is about 9% too high.  Second, even though I've been off the pace training wise, I couldn't keep the power down - it just loves to go fast! So I was 285W average rather than 260W on my other test rides.  Third, it was cold and windy so aero wasn't optimal at all.  After all that... I was about 2kph slower than my best on the TCR 

Overall, the test was a bust, but the bike was lovely.  More power for less perceived effort, and came off it feeling fresh unlike before where I would be fighting the bike and finish with a sore lower back and burning glutes.

One note, the narrower bars take a bit of getting used to out of the saddle, had a few minor wobbles due to the reduced leverage.

Also the seat post doesn't allow me to attach my existing tool bag - will need to come up with another solution. I asked Chris if the rear bottle cage mount from the TT bike could be used (he had previously said the seatposts were the same) but he said it would need riveted - there are no holes in the road version by default.  Not sure if they could be added when ordering?

Weight, I have no idea. I'm 80kg, didn't feel much different from the TCR built up.

Looks wise, I think it's great but the UD Matte finish is not perfect. There are clear joins where the carbon sheets overlap most noticeable around the head tube. It also has sections which look dusty or smudged. I'm sure a clear coat paint would solve this but it doesn't bother me.

Parts
Shimano 105 R7100 (2x12) stripped from the 'donor' 2024 Giant TCR
HB-050 380/110 integrated bar and stem
New PraxisWorks T47 BB
New Shimano R7100 160mm 50/34 crankset

Money
1750 for the TCR from which I kept the groupset and wheels only
-300 for the TCR fame (hopefully)
500 for the AeroTrace frame, stem, bars and seatpost
115 for new cranks
200 for the build including hoses and BB
2265 total

I doubt you'd find a bike this good off the shelf for that, even considering that buying a whole bike then using just the groupset and wheels (and then only temporarily) is a horribly inefficient way to build a bike!

Hey guys, does anyone have a photo of the saddle clamp assembly they could share please? I was trying to loosen mine to get the saddle further forward on the rails and over did it, the whole thing came off and fell on the floor. It's now a 6 piece jigsaw puzzle and I can't work out how it should go back together. Thanks!

BTW I have the bike built and have been out for a ride - TL;DR it's great. Will write up more soon.

Stand down, I worked it out. Managed to grab a still from Patrick's video which showed enough detail. I'm not sure how long the little rubber piece will stay on or what it's for, but the saddle is rammed forward as far as looks safe, and is rock solid.

Size 58

Who would have thought brown could look so good? It's lovely, honestly.

Mine and at least one other I've seen on here have quite an obvious line between what I assume are two different orientations in the carbon layup, to the rear of the headtube.  Is it the lighting, the colour, or maybe some changes to the manufacturing process?  I don't mind it, but it's the kind of thing once you see you can't unsee.

BTW I also have the 'skipped leg day' look with my current wheels but unlike you I will have to stick with them until I can afford some deep sections next year...