I saw it on Saturday night--looked sold out to me. I was sitting in the balcony and every seat was taken. A few people left in the middle of act 1, but that was because somebody threw up... smelled awful.
The show wasn't really funny to me until towards the end of the second (third) act. It was alright before that--but that's when I really started laughing out loud, and I'd say it was one of the funniest moments in theater I've seen.
"If it walks like a Parks, if it wobbles like a Parks, then it's definitely fat and nobody loves it." --MA