Well, I gave up and bought Superman: Earth One Vol. 2. First of all, I have to say that I had a blast with this GN, much better than the first volume for sure. Plus, we get some creative reinterpretations of certain Superman foes.
But I also noticed something: the answer to whether Superman: Earth One takes place in the same Earth as Batman: Earth One. Because some people have been wondering about this. Well, not anymore, whether it's a yes or no, that answer is here.
Ultimate DCU, anyone?