I just wanted to say that I can completely understand the problem with making a decision, I drive my DH crazy as well. It took me for-EVER to finally decide which convertible carseat to buy. We actually went to Babies R Us and stood there trying different carseats for...umm...about two hours...and this was the second time we had been there. Haha. We finally decided on the Evenflo Triumph (my son is only 15 lbs, 26 in), and only because when we tried him in the Britax, the straps didn't sit well on him, and the straps on the Evenflo did.
So I would have to agree, even though I'm not at the stage yet, that it matters most what seat your DD fits well in. Because I was all set and ready to buy the Britax, but I didn't feel it would protect him well if it didn't fit him well...Good Luck with your decision!!!