I have seen both, and except for a few color issues, I like the HC1/A1 latitude and picture over the FX1/Z1 (hate over saturation). But the low light sensitivity is what I imagine might count with a GG's darkness.
Why don't you look over at the Elphel thread. I have just come to the sudden realisation, that sending the bayer image monochrome compressed could give you sufficient quality. Unfortunately, sweet 2:1 720p compression (to preserve color accuracy more) might have to wait till a future version of the camera (the current one lacks the data rate I understand). At the moment we are waiting for the 353 version of the camera, which comes with significant improvement.
http://www.dvinfo.net/conf/showthread.php?t=63677