Which is why we need more tests comparing both. I don't see any problem with having dark blacks. But we don't have enough materials yet to say which of this camera offers the best details in blacks.
From what I have seen so far is that samsung seems to prefer offering a contrasty but clean image, where you have to work in camera to get what you want after. Also - imho - I think Samsung offers more interesting colors, which means easier work in post.
Whereas Panasonic started giving lots of tweaks in the gh4 (cine-d, master pedestal, curves) but with a codec breaking appart very quickly in post, and with a very mushy result most of the time (except when you just select cine-d and leave everything else to 0). But don't get me wrong, I love the Gh4 (happy owner of one and probably of a second one in a few weeks).
However in terms of details I think there is absolutely no hesitation. But details is just one part of the equation...!