I bought this about three months ago and it was the best thing I could have possibly done.

This seat keeps a child in a five point harness until 80lb! Twice that which normal seats will take. A child can stay in full harness till 4' 3" tall. The seat itself is steel reinforced to deal with the extra strain, and it is just about the strongest seat on the market. There is a Britax equivalent, but it is a huge, wide seat. The radian is thin, because it is steel, and you can fit three across the back of most cars.

Children are safest in a full harness, so I am happy I can keep her in this as long as possible.