yeah ive seen that before. im assuming the most important part of that comparison any of that is the infinitesimally higher self noise. regardless of sensitivity, they both handle equivalent input levels.
sensitivity is not completely out of line considering the cmc6 is designed to drive high-level balanced equipment and the cmr is designed to feed lower level unbalanced gear.
also i beleive the 79db S/N is more a function of the capsule itself, so should be virtually identical.
capsule noise should exceed preamp/body noise of either setup for all intents and purposes
Here's a comparison, but I'd guess the SNR is lower on the CMR as compared to a CMC6
MK4/CMR mk4/CMC6
Sensitivity 8mV/Pa 13mV/PA
noise level 29db CCIR/18db AW 24dB CCIR/15dB AW
S/N level not published 79db-A
max SPL 130dB SPL 132dB SPL