I'm quite sur that Noel would agree with you about the limitations of 8 bit processing. He refers in his post to the smarter implementation of an 8 bit codec by Canon by the higher allocation of information to critical tonal areas. As here was stated from various people who did work with the C300 that trick really seems to work.
Referring to the C100 I deeply hope that trick will work with its AVCHD 4:2:0 codec, too. Not to mention the HDMI-out.
Yes I understand, there is no doubt that the 8bit output is very nice at this camera. I would like to see the same viewfinder on both cameras. The C100 can differ rather in something other than in EVF. The 10bit output versus the 8bit output could be a nice option at this price level and makes more sense for me than a worse EVF on the C100 (with AVCHD 420 codec for the internal record). I can only hope that LCD on the C100 will be ok.
