DCnU Superman is undoubtedly stronger [and more durable if you extrapolate him casually handling Earth weight pressure for 5 days without sunlight]; sticking a bit on durability, his invulnerability now far more encompassing than before [while even before his inside were very durable - Manchester Black pointed to that, for one - now, even his brain tissue is capable of withstanding tesseract explosion and makes the Anti-Superman army afraid they'd get crushed if they tried expanding inside his head, not to mention Captain Comet pointing out that his telekinesis has absolutely no effect on his super-cells], more consistently shown as a genius, more decisive and aggressive; stamina, I'm not sure, given the fact that benching Earth didn't seem to be a big deal for him, so take him doing that for 5 days with only a sweat to show as you'd like; he definitely has bigger solar reserves; his eyes are now capable of 'emiting all kinds of radiation'; he gets mad respect far more often than before, both on his in-Universe stature as the most powerful hero [which isn't a surprise, since he needs to be built up as the new Universes' top gun], aswell on his abilities.
Pre-Flashpoint Superman still remains as superior in terms of speed and its uses [though the feat with DCnU Superman reading all of the medical text published, ever, is up there in ridiculousness], has shown greater power output in heat vision, has better senses [eventough DCnU Superman has a very impressive showin in the Red Hood & Outlaws issue], more skilled and experienced, and far better WTF feats [singing Darkseid out of existence and the like] in general.
So, yeah.
