Experience with the BlackMagic Design ATEM Television Studio?

I might be purchasing a BlackMagic Design ATEM Television Studio for a sports broadcast next weekend. If there is anybody who has one or had one, please let me know your thoughts on it.

What I know so far is:
No multi-corder (individual ISO recordings).
All cameras have to have a matching resolution and frame rate.

Some claim they had issues with sound. I will be using a mixer and feeding the audio through a camera XLR input. I'm just wondering if this might be an issue when switching shots? Can the audio be present in every selected camera shot?