One thing that no one else has mentioned about the britax is that it has the EPS styrofoam (like whats in a bike helmet) around the head. Last I knew, there was only one other seat (a Graco something or other IRRC) that had that. IF you look under the cover of most seats, there is just some foam to provide (minimal, IMO) padding, and then the hard plastic. It may meet the saftey standards in the US, but that doesn't make it good enough for my kid, yk?
Go for the Britax, it is so worth it. My britax is the *ONLY* thing I have researched, chosen, and purchased new for my kids. I get everything else on the cheap or hand-me-down, but not carseats!