Like I said, I am all for people not liking the HD800 because it is too bright or fatiguing and all the tonal balance stuff. I personally EQ it myself because I like a slightly warmer tilt. And while I am not a hardcore objectivist, measurements do give very goo insight into the capability of a driver's ability to properly reproduce sound. But if you don't hear the HD800 as having a soundstage that is different than a typical open back, then I am inclined to believe the HD800 you heard was faulty or the ways in which your ears hear soundstage is just on a very extreme end of the hearing spectrum compared to the average headphone enthusiast. Of course speakers have a superior soundstage reproduction compared to any headphone, that is not debatable, that is physics. But to say the HD800 is the same as all other headphones just doesn't make sense.
And again, I love the M1060 and think it is a fantastic headphone for the price. And that is totally reasonable that you enjoy it more than HD800. I'm even fine if people don't think the HD800 is worth its price or is overrated. But it is unfair to say the M1060 outright "outperforms" the HD800 and that it can't compete with M1060. If as you said that measurements have no meaning, and we all know tonal balance is just individual preference, then how can you make a blanket statement like that? At best, you can say you prefer M1060 to HD800 and that you think it is a better value, and I think that is perfectly valid.