The ATEM Television Studio HD is how I got my start filming and livestreaming conferences and events. It's been a great switcher, even with the limits of the older ATEMs like the lack of scalers on every input.
I used this on my own livestream until just a couple weeks ago as the final downstream M/E to overlay key/fill graphics from a Hyperdeck and Ultrastudio from OBS. You can see the gear diagram of how I had my studio wired here: https://h2rgear.com/plan/2TVJTpgbGDmtk6PViGcq
I replaced the internal fans with the ultra quiet Noctua fans, and it is nearly silent now! That was the main thing keeping me from using it in my studio before, but the quiet fans make it nearly as quiet as an ATEM Mini!
There are some scuff marks on the top, but the front panel is very clean and everything is functional.