That's a good selection of machines you've found, I quite like the Servis Quartz myself, I used to have 1 of those but it was a rebranded Electra. It was a late model and I spent much of my childhood in front of it and has seen itself in 3 different houses lol!
It was a decent machine that was easy to use, I quite liked the indicator lights which tells you what stage of the programme it was at and that it did nice water levels for rinsing too. The maximum spin was only 900 RPM which sounds average nowadays. I also remember the Cancel button which means the drain pump can be activated at any time, even when there's no programme on. There is of course the big panel door which is a bit like what you see on a condenser dryer but the drum capacity was small at only 4KG which meant that on some days, we had to do more than 1 load a day lol!
My model lasted an impressive 11 years considering the longevity of machines back then and my model was in white with dark grey although I do recall seeing the same machine in all white.
I liked that machine very much and have many found memories of it. So, that's my experience of having an Electra (Servis Quartz) washing machine.
BTW, If you find anymore interesting machines on Ebay, let me know!