Has anyone mixed and matched footage? Looking for some advice on doing that. Presumably you'd shoot in 720p on the EX. Any other advice?

Yeah...I've played around with that problem. Using Avid, I can make the color maps match each other pretty closely. The edge definition, however, is kinda a give-away. I can add a little bit of gaussian blur to the EX1 footage to make it match more closely....never perfect...mostly DOF differences, but, only the trained eye can understand why.