The Britax Boulevard is the way to go in my opinion. Yes, it's expensive. But it is SOOOOO worth it. Adjusting the straps is super easy, installation is easy, the straps don't get all twisted up, and the seat is comfortable. My youngest is a sturdy 40 pounds and has a long way to go before she grows out of it.
We were in a horrible car accident when our oldest daughter was just 10 months old, and the CHP officer who responded told us he was pretty sure she would have been dead or at the very least, seriously injured, had she been in a lesser car seat. As it was, she was completely unharmed. From that moment on, I became a die-hard Britax fan! You can't go wrong with their car seats.