[WalterSchulz]

With 600D you are stuck to 1620x912 in video mode embedded in 1080i59.94 8-bit. Black borders around and you have to crop and - maybe - scale up. 200D HDMI stream with ML is clean with MF but AF will still draw a focus rectangle. But at least true FHD via HDMI.

AF with 600D in liveview: Phase detection only. Focus hunting galore. 200D comes with usable DPAF.

I prefer 250D for streaming. Dual display support, no 30 minute limit for HDMI out (but cam display will go dark until some button action).

[larodi]

But there’s no way to skip HDMI right? I mean I’m not familiar with ML, but think whether some wiring can be spared. Don’t these cameras expose wifi of some sort?

IMHO even 800x600 is okay for most streaming needs. And particularly when sound quality is of primary importance.

[WalterSchulz]

600D doesn't have WiFi. You can stream via HDMI or USB. USB stream for cams not supporting UVC (in general every EOS before Digic X and even some of those) is limited to 576p. Don't get your hopes high subscribing to EOS Webcam Utility Pro. Canon says it is able to deliver 720p and 1080p but they are scaled up from 576p. And you need a dedicated mic. No audio support via USB or HDMI in early cams.

[larodi]

Thanks for taking time to explain. Perhaps I should also take time to share our setup in some sort of blog or gist.