77 OLED LG tv.
I upgraded to gig with Comcast. It's better than the 200 I had before. One thing that is quite obvious is how quickly the 4K picture "forms" when starting in the middle of a show. Like stopping at night and restarting the streaming the next day. I don't get many reductions in pix quality during a show either.
In other words, the picture would be low-res for about a minute or two with 200, and about 10 seconds with gigabit internet.
The other thing I notice is the blacks/shadows are no longer pixelated with good content. Prime 4K such as on the the show, "The Expanse" is clearer and sharper, as are many shows with great 4K content. This may be due to the equipment on my side, and how they deal with streaming. But the results are obvious.