Hello there,
I just got my hands on a 15" Macbook Pro with Touchbar and a few video capture cards and wanted to share the results here.
Setup:
15" MBP w/touchbar
Cameras:
All cameras were connected through SDI 1080p 29.97fps
The Epiphan device only supports 1 camera and it had noticeable delay at 7.5 frames. I would even suggest that the frame rate was varying a little bit.
The Duo 2 inside the Sonnet Echo Express captured flawless video from 3 cameras simultaneously at 6.25 frames delay.
The Duo 2 supports either 4 inputs or 4 outputs which you can configure as you like: 3x1 ou 2x2, etc.
The Quad 2 inside the Sonnet Echo Express was a bit faster at 5 frames delay while capturing video from the 3 cameras.
Millumin always humming at 60 fps and Activity monitor reporting the system did not flinch at all.
I also tested 4 cameras with the Quad 2 and you can go up to 8!
You need these SDI adapters for the Quad 2.
If I get my hands on a USB-C to thunderbolt 2 adapter I can also test an Ultrastudio mini recorder, to compare.
Hope this helps.