We were going to both. My wife is leery of the al-you-can-eat churrascaria places. I have walked by all the ones in River North but never have eaten at one. They look like they are geared for the real tourist. Looking forward to eating at the Purple Pig.
Well, if its a choice between the two, Purple Pig wins hands down, though of course they're entirely different types of places.
As far as churrascarias go, I'm a traditionalist and prefer a more traditional churrascaria. Still, Zed 451 serves a certain purpose.