Generally NDI is not widely used in professional AV. There's a fair bit in prosumer, and a _little_ bit in the low end of pro. But the fact that it's a proprietary protocol (they can claim it's “open” all they want, but the SDK is closed source, there is no spec and they sue people who make open reimplementations), has poor image quality (it's roughly MPEG-2 intraframe, i.e., not very good), has poor latency and isn't very reliable makes it a no-go for most larger installations.

I would argue that it is heavily used in professional AV, but not as much in high-end installations and usually not in broadcast setups.

It is certainly not open and doesn't compare to ST2110. I was mentioning it for compressed video streaming.