I went to Malagueta two Fridays ago and Girossol last Friday. I know that Malagueta has been raved about here, and maybe it's just a matter of adjusting my expectations (when I think Brazilian I like to think of big hunks of marinated meat and not so much creative cheffing), but I much preferred Girossol.
At Malagueta, I had the special, a soft-shell crab with some some kind of sauce with rice, and my dining partner had your basic sirloin. The crab was alright but didn't knock my socks off and the sirloin was disappointing. There was a very good heart-of-palm salad to start off with, though.
Girossol was wonderful, however. Refreshing hearts of palm with olives to start off with, great churrascurria (sp?) hunks of meat (satisfying that primal urge) and yummy feijoada. To be fair to Malagueta, I was with a bigger crowd at Girossol and had a wider range of choices.