The most striking thing about my meal at Buenos Aires' Kosher McDonalds (the only one outside of Israel, according to my guidebook) was not the absence of cheese on my Big Mac, but the fact that the hamburger patties tasted like beef. Try tasting a McDonald's hamburger patty on its own sometime - you'll find your American version warm, salty, and slightly meaty, but by no stretch of the imagination will you be able to say it tastes like beef. This Big Mac's hamburger patties tasted like pure, grassfed Argentine beef, and to tell you the truth... I found it a little off putting.
Which is crazy to me - I'm a firm believer in the virtues of grassfed animals and responsibly raised crops. Truthfully, I don't even like McDonalds, and had always thought that a fast food hamburger with some quality meat would be a major breakthrough. But as I chewed on my hamburger I couldn't get past the undeniable flavor of beef in my mouth. It actually turned my stomach a little; it's not that I have a weak stomach (I ate veal brain ravioli for dinner last night without a twinge), it's just that my Big Mac tasted wrong. I've deicided to not worry about it, and leave McDonald's to engineer their burgers however they'd like. There are plenty of other places to eat.