Post 6 is updated.
How does it ride?
I have pushed it a little bit but still need some fine tuning and bikefit. Cleats have been adjusted. My reference track over 40km was 1,3km/h faster with the same pulse. Wind conditions may be different and no watts compared.
My CX have really rapid steering and that´s why I want a road bike. However, this is very stable with 28mm so I think i will look for something else. I swapped to 25 again and will probably try again this afternoon. I´m looking on P Zero TLR or TLR SL to get something lighter. GP5000 TL vs GP4000 S2 with race tube is 55 grams heavier in system weight. I feel that in the hills and corners. But it feels good down and on the flats. I have 6kg front and back on the TL.
It´s hard to say something about frame stiffnes compared with my alu frame on the CX. It absorbs small road vibrations better.
It´s a comfortable and stable ride. Like I am on rails. The heavy tires does give a feeling to understeer. Top speed 57,6km/h so far but 52/11 is capable to a lot more with 100 in cadence.
Weight without bar tape and chain was 7,4kg GP4000. With chain, bar tape and GP5000 is 8,4kg. Lighter chain and tyres would be nice but after all, it is a big 595 bike.
Ultegra Di2 - I think it shifts a bit slow on the rear when it does the sync shift from big to small ring in front. It´s like it´s waiting some milliseconds before it shifts between the cogs on the rear so I will spin up a lot first and then stabilize on correct cadence. A wire was actually much better her. I dropped to small ring and push the right lever 3 kogs the same time.