Just did my first semi-wet ride after installing my 2nd rear derailleur (after 2 months of not being able to use it). This time with dielectric grease on both derailleurs.

First ride, and the shifting was incredible. So far no issues with the grease. Hopefully this derailleur will survive the weather in the Netherlands.

Ltwoo was helpful with their customer support, however the process of confirming the issue, and shipping the new derailleur took a sizable amount of time.

I want one now.

What is your current hierarchically sorted list of bikes to build?

On the actual topic: I ride a Speeder, and the frame is great. I only had some minor issues with play of the headset bearing, but nothing some tape (again thanks patliean1) could not fix.

I am having issues with my Erx- randomly working/not working and being slow to respond (it's been very wet here) while working fine with the app but not the brifters (which have new batteries in them and the system is fully charged).  Would you be able to describe in more detail what you did with the duct tape? Did you wrap a small piece around where it plugs into the mech or ?? I'm not quite sure how to follow your suggestion and I would LOVE to have a working set!

Step 1:
Disconnect the cables from both derailleurs
Step 2:
Be absolutely sure there is no moisture in the cable or port on the derailleurs. Thoroughly inspect with a flashlight, and let it dry overnight if you want to be absolutely sure.
Step 3:
Rear derailleur: create a strip of ductape (2cm x 5cm), connect the cable and wrap it around the derailleur + cable to make a tight fit. Press down on the ductape to ensure no moisture will get in. Make sure the tape surpasses the "cup" (poor design) which fits the cable.
Front derailleur: unmount the whole unit so you have better access to the port. And repeat the process for the FD. This one of more finicky, but just try to make sure you have a reasonable connection. The FD is less likely to ingress water as the port is downward facing, whereas the RD is essentially a convex shape, waiting to pick up rain.
Step 4:
Ride!

Have you ridden the Shimano 12s Di2?  Are they smaller than those?  They're already very low volume.  They look a bit bigger than the Shimano brifters, though I haven't compared them side by side.

My other bike has a 105 Shimano set, and they do feel more natural to my hands. However, after playing around with this setup a little bit more, I came to the conclusion that I have not set them up correctly. Will hopefully get them more comfortable within the next couple of days.

I am not trying to add negative publicity, rather add a simple piece of truth, and a way to deal with it. Again, now that I used the tape, the groupset is working like magic.

Ltwoo groupset
I just finished my first ride where I did not have issues with the groupset. For anyone with an ERX / ER9 groupset, I suggest you add some ductape between the connectors for both derailleurs. After I did this, the groupset has been incredible, and is a dream to work with. Especially for that price (~500 eur).

The only downside now is how my hands fall into the shifters. This is obviously a personal topic, as the shifters might fit you like a glove, but it feels incredibly awkward, as if my hands are simply too large. I will play around with the shifter position on the handlebar, but if that does not resolve the issue, I might take the route of 3d printing a mold that perfectly fits my hand (on top of the shifter). Has anyone thought about this before?

Speeder frame
This frame is asking for speed, and when getting in the aero hoods position, it is incredible how easy it is able to hold high speeds. 62 kmphs was no problem on an extended piece of flat road.

The frame feels stable and stiff, and regardless of how much power I push through the pedals it remains composed.

Finally, I have had an enormous amount of compliments of people while riding / cleaning the bike, and I have to wholeheartedly agree with them that it looks absolutely stunning.

It indeed was you Joegal! Thank you for the suggestion.

No, I did not weigh the parts separately. The total build comes down to 7.8 kg (as seen in the picture). And to my calculations, it does mean the parts (as least of a sum from Speeder Cycling) are close / identical to their presented weight.