We have installed several of these to do what you just described. Couple of caution notes. The ATEM does not pass HDCP sources which is the encryption for HD content. This means all Blue Ray DVD players will not connect. Also, some regular DVD players will upconvert, just make certain you can set the output to 1080i. Most default to 1080P which the ATEM does not support. We use a Sony DVD player which is working fine. Most laptops connect just fine.
Also, the entire switcher works at your specified resolution. (720P or 1080i) and either HDMI or SDI.
You cannot find a better value or better performance if you work within these limitations. We are producing a Friday night football game using an ME1 with Panasonic HVX series cameras and delivering in high definition for our local NBC affiliate. It is that good.
Jim
M&M ProductionsUSA