@ geekapproved: Yes, I would buy the SeaSonic M12II over the Corsair, as the former is modular, which will make cable management easier; if there's a cable you aren't using you just unplug it instead of having it tie up space. 30W isnt going to make much of a difference one way or the other. It's also prefer to support a company that makes a product instead of rebranding it.
Personally, I'd trade those insignificant 30W for a modular design, but to each their own. Like I said to the OP: "Either way you'll be all set. "