Ah so you bought it for the badge - I understand.
As the owner of a BMW 535d and an i3, and as someone who built his own road legal sportscar (not from a kit), I understand engineering pretty well. Unfortunately I think the Mercedes you speak of was lost a few decades ago but I take your point. There is a counterpoint though, in that part of the "price" of a well known branded product is purely for the badge. Personally I'd rather have the substance than the marketing, especially for a brand which is IMO trading on past performance.
Unfortunately in the world of LCD displays there are very few manufacturers of panels and LG is one of the main players. The quality of the panel they provide comes down to the economics of the product it will be fitted to. In this regard, LG have much more scope to include a high-end LCD panel in a $1300 product than Eizo have in a product which is around 60% of that figure. No doubt there is a bit of a premium in the LG product due to the uniqueness of it at this point, but I think the LG panel is excellent. I also far prefer the look of the back of the LG display compared to the Eizo which looks like a bit of a dog's dinner to be honest, with exposed metalwork around the clunky connectors. If you care about good engineering then I'm sure you appreciate the importance of the bits you don't look see everyday as well...
On your final point, 2560x1440 logical resolution is indeed the sweet spot for 27" but the 5K monitor allows you to use 4 physical pixels for every logical pixels which is what gives the retina display its gorgeous image quality.
Anyway, glad you like your Eizo as much as I like my LG 5K's. Win-win.