Hi Troels,
After a few months of enthusiastic listening, I want to give you a short feedback on the 3WC-10 Level 1 BE version. The sound is simply overwhelming, even with a small Bluesound Powernode streaming amp (NAD tech inside). Tonality is great, and to be honest, even with the perfect mids and highs (BE-version, especially the deep, fast and clear bass in my small 16sqm office room surprised me most.
But what really struck me is the transparency, 3D-panorama, the easiness, how the speakers completely disappear from the music scene. And even after months of listening at rather low volume levels, the sound seems to be loosening up further. I have had big B&W 802 diamond speakers in my living room, but this sound is clearly better, without a doubt. The combination of base, airiness and precision is truly unique.
 
Attached a few pics from the build. I used 2 tricks which might be useful to other builders:
As I do not have a table saw, I have built a wooden guide for the sliding rail to ensure 100% identical board lengths when making the 45° cuts. The first 45° angle cut is easy, but the second cut decides the exact length of the board. So for making the 2nd cut 200% precise with the exact length, I fixed the guide on the board I want to cut, push and fix the sliding rail for the circular saw against the wooden guide, done. All cuts were 100% exact by 1/10mm. See pics.
Second trick is to actually tape the boards together. For that, I layed out the sidewalls, top and bottom in a row on a long table and taped them together with strong package tape. Then I added lots of glue to the 45° joints - and simply fold the box together. Last but not least, I glued in the front and the back. Then, I added further tape with a lot of tension. Finally, I added a few clamps. 
Both procedures are worth trying out. They helped me to build much more exact than in the past. Additionally, I inserted a diagonal board for the midrange enclosure with some aperiodic damping instead of the rectangular box in the original plan. Might help to even better eliminate resonance and reflections from the real membrane area.
Thanks for your inspiration, the great kit and the simple and reliable shipping process. Next will be TLS 1 or 2 for the living room. 
Feel free if you want to publish this on your website.
Best wishes,
Thomas