Hi Troels,
I hope you are doing well.
I have a question regarding high efficiency but first wanted to share that I've recently completed the Faital 3WC and am currently working on the Ekta mk2.
I am not skilled at woodworking (nor have the tools) so ended up purchasing both cabinets from Ebel Holtztechnik. I have been extremely happy with his work, everything top notch and fair price.
In my main system, I use a solid state Benchmark system (LA4 + AHB2).
I've never heard the ScanSpeak Illuminator drivers and am looking forward to compare them to the Faital 3WC. The system is in a dedicated listening room, with some room treatments (picture with messy system attached).
Regarding HES, I have a soft spot for tube amplifiers and have built (and sold) quite a few over the years. I am working on a high quality 300B amp, but have never heard it with truly adequate speakers. My 300B amp will only have a single 8ohm secondary and max output of around 10W. 
I will try them with the Faital, as the impedance looks fairly friendly, but looking through your site, it seems like the TWTQ will be a good/better fit?
I read the original article, and just wanted to validate that the mk3 version has a similar impedance profile?
Thank you very much!
Itsik