Honestly, if I trusted the friend to be able to accurately and honestly answer the Britax questions, I would be comfortable using them.
But to be honest, I do think seats have varying quality safety. Passing minimum standards does not mean they all pass equally. There ARE stats on things like head excursion, etc so if's not true that we "don't know which ones are better."
Proud SAHM to Connor (8-6-10)
and our little