The primary complaint I've seen for this TV is that its not bright enough compared to LED models, but I've not found it too dim, even in a room that gets lots of morning sun.
Another OLED concern is burn-in. After 2 years of 90% Netflix/YT and 10% gaming (mostly Forza Motorsports 7), I have not seen any signs of burn in. Apparently the built-in image shifter/orbiter works well.
EDIT: In terms of smart TV misfeatures-- the voice search requires a scary opt in that I've never done. Aside from that, I'm able to disable most tracking, and I've not seen any targeted ads.
The biggest issue I have with the TV is that the LG the "magic remote" is incredibly annoying as it pops a cursor onto the screen randomly when moved.