My DD is 4 (5 next month), 44" and 35 lbs.
In the past year, we have used: Frontier 85, Pinnacle, Pioneer, Argos, Performance Sport, and will be trying the KidsEmbrace shortly.
So far, Performance Sport is the winner for us. Love it.
I feel like the Pro/PerformaceSport is really under-recommended on the Interwebz. It absolutely has its quirks, but for kids who aren't bothered by the belt routing (none of mine have ever been, and I've had five or six use it,) and who won't hit the 52lb tether limit, I think it's a great, often overlooked option.
LIS, interested to hear what you think about KE!!
Glad to hear you both like the Prosport! I am fairly certain that is what I am going to replace the BLVD70 with sometime in the next couple of month. DD2 still fits in the BLVD70 but I am starting to dislike the high base. I could move her in the RXT full time, but I have my neighbors dd a lot and it is what I use for her. Plus, I am itching for a new seat!