Thoughts, not all of Europe has ffing standards at 9 mos, but that is actually a popular stance for most of the world. Those countries require top tethering though which helps w/ neck injuries for ffing children. Like someone else mentioned, they cannot have chest clips on their seats. Sure, some kids will be able to get out of the straps, but that happens all the time here w/ kids w/ chest clips. I saw it the other day w/ a little boy (3) in an Marathon.
The Cosco Scenera is a great seat, it lasts a lot longer than some of your more expensive seats IMO (Comfortsport or Triumph). He was in it rfing till 34# and the top slots are even w/ his shoulders now so he could technically use it for a little while longer, but it's Evan's seat now in DH's car. CS and Triumph only go to 30# rfing and I'm not sure how anyone would make it that long b/c they have such low backs.
Yes, the Britax seats are great, but w/ twins, I can understand how it wouldn't be a reality. Britax isn't the be all, end all of seats, but yes, I agree, you'll get lots of use from them. There are 2 other higher limit options I'd mention though. Fisher Price has the new Safe Voyage DLX for $180 that harnesses till 55# and has the same harness slots as the Britax seats. There's also the Sunshine Kids Radian for $180 (we have this one) that harnesses till 65# and seems to have slightly higher slots than the Britax one. It can also tether rfing, which the FP seat can't do. You have to oder this one online, unlike the FP ones which you can get at Baby Depot if you have one. AJ isn't quite 3 and already on the top slots of his seat b/c he's so long torsoed, he's been through several seats already and we should've just bought an expensive one to begin w/.