Parallax was able to erase timelines/universes, began manifesting his own universe, and held his own against Corrigan-Spectre while in the process of creating said universe.
Cosmic Extant (with an incomplete Worlogog) was able to control every fundamental 'law' of reality, which allowed him to create his own universe with a gesture.
Feat-wise (ie. hyperbole/speechification aside) the DC fellas come off as more powerful to me... But it's arguable, I suppose. Meh, don't really care either way. /shrug