I'm not sure it is a good idea to compare raw data from different systems with shots taken in different lighting etc. I understand your predicament but I reccomend you taking a test shoot with both backs at the same time and seeing for yourself. I have about 40,000 raw files from my P25, all people pictures, shot in natural light and exclusively at f4 and 400 ISO. I've a system of forcing exposure and pulling back in C1 that gives me the look I want. If you were to just open my files in C1 before adjustments you'd probably scream. I use a system just like I did on film of overexpose and under develop. The 'look' I get is spot on for what I want and the skin tones are sublime. If you shoot flash or at 100 iso then my shots would be of no use to you whatsoever. Mastery of Capture One is really important too. It's not hard to get great pictures, it's just too easy to mess up if you haven't set up the defaults to suit your workflow. You have film curve options, look (styles) options, output colour space options, to be tweaked then just the usual contrast, exposure, colour, noise cancellation, anti banding etc.
It took me about a month to really get set up and start getting the best out of my P25. Partly because RAW working was new to me but also because I had to get used to the subtle tonal options that are available to you by a change of exposure or a change of film curve. The pictures were good out of the box but like with most photographic processes the persuit of excellence takes you deep into experimentation and critical analysis. Two years on, my P25 is a tool I just use without any doubt of how to make my pictures 'sing'. It's just brilliant.