I'd keep Juan -- I love it when Britt and Juan go at it on a hot topic. I'd get rid of Jeff "I'm-too-wishy-washy-to-express-a-real-opinion" Birnbaum.
I get the impression that if anyone as much as raised their voice to Jeff Birnbaum, he would get up, leave the set, (while on the air) and never come back again.