No worries, I know what you mean. These were raw files and yes there is a ton more detail than what is being seen. I could bump up the shadow detail a bit more yes, and part of it is how this website transforms the images after being uploaded. But I'll post a couple of the shots with the suggestions you mention, thanks!
Yes the space is accessible by a pro photographer friend of mine 24/7, and yes it is actually a huge interior conference space adjoining a studio rented by my friend. The light from outside was actually a lot brighter than it looks, which is why I was shooting faster shutter speeds to get more contribution from the two strobes.
So, why the D4? Well I've used the D800 previously on my other shoots and love it, and just wanted to see how the D4 performs in that studio setting and I was pleasantly pleased with the files and the resolution at 100 ISO. I'm so used to the D800 images being "more than perfect" insofar as resolution and detail in shadow areas. But after I got the D4, I noticed right away on the back LCD screen the images had a different quality to them that is hard to describe. It is almost like looking at an image taken with film. It isn't perfectly super resolved, but it has a nice tonal quality to it that is different from the D800. Also, if I tested the D4 and D800 side-by-side, the D4 always had significantly brighter images at the same settings (ISO, aperture, shutter speed, same lens) so I could get away with faster shutter speeds or smaller apertures, and with that, I can better overpower ambient light with the strobes. So it was basically a test of how well could the D4 manage in a setting that really belongs to the D800?