After seeing the ad for Boi Na Braza (in Grapevine, near DFW) in American Way a million times, I finally gave it a whirl for lunch last week.
I've always thought of Fogo as the rei of US churrascarias, but I would have to say that Boi na Braza excellent -- while it was only my first time, I would say that it's probably in the same league.
(I know this is about Chicago venues, but I thought I would drop in another recommendation as well.)