A wonderful friend of mine just did a post on her blog about car seats that was really an eye-opener to me. You can read it here. Several people have asked me questions about my decision to purchase Britax seats recently. I am very glad I was able to buy them and I love them. However, if you can only afford the basic seats I think it's more important that you use whatever seat you've got correctly or in a way that maximizes their effectiveness and doesn't just satisfy the minimum requirements of the law.
I'm switching the Rabbit back to rear-facing. Those crash-test videos are pretty convincing. And Fish is definitely going into a 5-point harness.
I've definitely changed my tune when it comes to car seats.