Kevin, I've got the LG B6 OLED. All the OLEDs of a given model year have the same PQ. As I mentioned, I also have the Sony 940c, 65" LCD. That's a full array local dimming display, so it was the best LCD of the year that I bought it in. As you may know, Sonys are well regarded for their upscaling prowess like the Samsungs, but here's what I've found. If I examine the screen from a few inches away, I can give a slight edge to the Sony over the LG. However when I move back to anything approaching a reasonable viewing distance, that difference simply disappears. They both look very sharp upscaling HD to 4K.
Now admittedly I watch no SD material, so I can't comment on that, but for HD material (which is the majority of what I watch), they both look extremely good upscaling. However there's no question in my mind, zero, that the overall PQ on the OLED is far superior to that of my Sony LCD. The Sony LCD, as good as it is since it's a FALD LCD, still can't keep up with the pixel by pixel precision of an OLED. No blooming, no off-axis issues, absolute blacks and some truly saturated colors, leads to a PQ that my Sony just can't match. Unless we get another technology, my next TV will be another OLED.
My typical HD content is via Directv, which like all the other guys, compresses quite a bit. Verizon's FIOS used to be the best for being the easiest on compression, but from what I've heard since I left FIOS, things have changed there too.
With all the multicasting that goes on even with locals, there's no longer a guarantee you'll get the best picture on your locals. Of course much of this is location dependent, but here in N.Y., they can easily have 3 sub-channels on any given main channel.
BTW, if you want to add to your 4K material and have any interest in shooting video, this is the kind of result you can get with your own equipment. I shot this a couple of weeks ago: