I bought a MediaLight strip (https://www.amazon.com/gp/product/B01HHHVL6U
- the 140cm version) for my C7 that's on a stand, with the screen about 14.5" away from the wall. Attached the the USB port on the TV, it'll turn on when you power the TV on and shut off on its own when you turn the TV off (and it finishes running any background screen maintenance it might be doing), which is really convenient.
We bought a bias light chiefly to help with eye strain in a dark room. It's not a totally light controlled environment, but it gets plenty dark (enough so that we run the bias light at its dimmest setting). I can 100% say that it helps for that, and we never wince when a moody scene goes to a sun-drenched HDR one. Contrast enhancement via bias lighting isn't really a motivation, since these OLED TVs already have perfect contrast (true black).
As far as aesthetics, I like having a bias light quite a bit. It feels a bit more custom/high-end to me, though that's the completely of personal taste. I have one friend that doesn't care for it at all.
You do still get the impression of an image floating in space when you're in a darkened room. Just now it has a bit of a halo around it.
Edit: Forgot to mention where I mounted the strip! It's near the top edge of the white plastic in back that sticks out from the screen. The MediaLight strip has an adhesive back, but it sounds rather permanent. I just attached mine with masking tape, since I want to wall mount the TV once we redo the living room. So far, it's been holding strong. Also, the 140cm strip spans the width of the TV perfectly.