I purchased (and I quote CNet) "The Best TV Picture Ever" one of those LG OLEDs.
To CNet's credit (and where/how I make MOST of my purchasing decisions) indeed, that TV to this day, STILL has "The" best I personally have ever seen.
The "Curve" - to me, made absolutely NO difference whatsoever no matter where I sat while viewing.
I do have to add that, 21 days AFTER the MFR's Warranty was up, did the unit DIE on me. (LG, you reading?) Thank Goodness AM3X gives their customers double the MFR's warranty (up to a year) and honored it. That TV was 3K$ (when I purchased it) and at least I was able to retrieve MOST of my purchasing $$$.
I replaced the unit with a 65" S@msun 4KUHD withOUT the curve, didn't notice a thing such as "hey, this picture looks too straight" or "I miss the curve look" - didn't notice any difference between EITHER my curved unit or my old-fashioned flat TV.
Side Note: As expected, 4K content is becoming increasingly abundant every single day. Many may not be aware of it - for example when I pull up any one of the "streaming" services I'm a member of on a computer/tablet there isn't any mention of ANY 4K content. (for obvious reasons, you/I couldn't view it on that device) but the UHD4K TV's have a modified version of the apps from those 'streaming' services that displays just how much content is available in 4K format. I subscribe to 3 streaming services and ALL three offer a modified version of their streaming app on my new TV that display their current 4K listings.
N3tflicks alone has quite the number of pages full of (either) up-converted movies to display in 4K format and/or those that were actually filmed natively in the higher resolution. UTub3, too has an excellent selection as well and it should go without saying the @mazon app also has some 4K content listed. (Again, keep in mind you do NOT see those listed if you cannot display them, such as on a tablet/computer/phone, etc..) If you can, I've just not came across or discovered those versions for my computer/tablet/phones, yet.
...so, on that last side note, pay attention to the 4K units if you're in the TV market. It is so much _not_ the hype 3D had, (3D? to me? just an added feature I VERY rarely used) but this 4K is indeed worth investigating to see if you can appreciate the higher 4K definition images. (Me? Those shot natively in 4K? Amazing, just amazing.!!!)