It is a "breadless" burger, if you forget the two coated deep-fried chicken fillets, that surrounds two strips of bacon, and two slices of processed cheese.
Freedhoff's food articles remind me of reading comparisons between Canon and Nikon cameras, as if each negative (no pun intended) feature is a positive. In this link he compares the Double Down to a "secret" McDonald's menu item, called the Mc10:35, because it is a combo of egg and bacon taken from the breakfast McMuffin, and added to the McDouble (replacing inadequate McSingle), at the changeover time between bk and lunch (apparently now popular in the San Francisco area .. so far).
Estimated calories 560, estimated sodium 1,300mg.
Nutritionally? Pretty much a wash. Yuck factor? Flip a coin.
The Double Down.
The winner will indeed be KFC. For a few minutes, consumers tasting this will feel like they've won a prize. Too bad that all those types of happy meals don't keep us happy after we consume them.