I love that they say it's the exact same thing, and then immediately they contradict themselves and say someone who disagrees with them is suffering from a placebo effect. Come on.
Oh and I'm an "actual photographer" and photo editor. So a different opinion here from someone in the same line of work as the person you quoted.
I have a 5K iMac and I have compared it to the ASD and the two have the same resolution, but the ASD is superior in several ways: backlighting, brightness, contrast, a bigger color space, and better control of image bloom and retention. I did NOT compare it to the LG 5k display as I don't have one available, but I've heard enough about the construction, the wobble, the ports that fail, etc., to know there are a host of reasons to not buy that one over the ASD.
That said I still think the ASD is more complex than I need it to be and the price is currently more than I'm willing to pay. But it's still a superior monitor and I can see it.