It's certainly not too big to TRY. If it's your first carry gun, I'd say it might be a bit big to START with. What the fellas have said above is true, and what works for some won't work for others, etcetera ad nauseum... But: it's also objectively true that a lot of people who own a lot of guns end up carrying smaller guns than a Commander because they feel it's just too restrictive--just a bigger set of sacrifices/compromises/whatever than they're willing to make in their wardrobe or whatnot.
If you're shopping for your first CCW gun I'd advise something smaller and probably lighter, to ease the transition to CCW. Not that a Commander can't be made to work--and be a great choice if you are one of those who will make it work for you. But there are reasons why the most carried Concealed weapon in America is an S&W j-frame (okay, I just made that stat up; but I bet it's true). And if you start with a smaller gun, then bump up to a bigger one, I'd bet even better money there would still be times you'd be glad you had the smaller piece.
Oh, and just for clarification, I conceal at various times a j-frame (of course); a Glock 19; a full size 1911; a 2.5" k-frame; and a couple of different 4" n-frames (but not all at the same time).