I guessed camera B as the Red and in fact, the footage from B is much more cinematic. From the deeper color to the softer image to the motion, I thought 'movie' more when I saw image B.
Sharper does not mean 'better', plenty of cinematographers use lens filters to soften images, especially for skin.
The RED has better color (and I am a Blackmagic user [BMCC]). From the softer blue sky to the greater depth of green in the opening shot to the blue highlights in the low-light shot, RED's colors were smoother and deeper though the BMPC had more saturated color. But again, saturation does not mean 'better' usually for films we are desaturating colors instead of oversaturating them.
Also, the BMPC's internal battery does not last 1.5 hours! Getting 30 minutes is more like it.
That said, I could never afford to buy a RED like I can with Blackmagic. I'm thinking of getting the URSA mini 4.6k.