Enterprise was just too sanitised in its early episodes. It felt more like TNG and failed to capture the pioneer spirit of the original seties. I agree that nuBSG was too dark overall for ongoing Trek but I also agree that featuring some dark story arcs in Trek is a good thing.
I aimed a bit darker for my youtube comic set just after the motion picture but largely because I wanted to rip off other franchises and write some amalgam stories. The big inspirations so far have been Alien and Babylon 5 but there are a few more I can molest before I'm done and zombies are definitely on the list!