I had a friend who calibrated tv's and the pq on his tv looked ridiculous. Washed out, almost no contrast, but you could "see the detail" in black areas. I can also see details in the shadows on my tv, even in scenes which also have areas which are supposed to be jet black (and are).
Also, he may as well have used his sub as a coffee table for all the bass it was putting out. I don't calibrate my sets, I tweak them until I get them as close to perfection as possible, then tweak again when I get "setting fatigue", same with my audio system, and I defy anyone to tell me my tv and sound system look and sound like crap.
And believe me when I tell you, I'm not one of those people who thinks the brightest display in the store is the "best". I know a good picture when I see it. My current tv is the "bottom of the line" LG 60PN5000 that I paid $558 for at Walmart.
Not trying to stop anyone from calibrating their sets if they want to. I just don't see the point. And no, it wasn't because my friend doesn't know how to calibrate. I've seen side by side comparisons of calibrated vs. non-calibrated tvs at Best Buy and other electronics stores and the "calibrated" sets look just as bad.