I enjoyed the episode quite a bit. The opening scene on the plane was pretty gross, and the exploration of it later by the FBI was pretty grisly, but the make-up effects were amazing. I liked Anna Torv; I didn't notice any accent waverings, though I was mosting concentrating on her eyes and smile.
Oh, and John Noble was great. The cow business was funny, and I also liked the reactions of the cute black girl in the lab. I could do without Joshua Jackson's character, who was annoying for the most part, but I guess he and the father come as a set.