Well I can heartily recommend the DuoLogic

Are you looking at the 1 or the 2?
I don't know how adjustable the Britax ones are (as I don't have them), but I love that the DuoLogic reclines, and has LOADS of room for my baby to grow. I've got a small girl, and she isn't anywhere near needing the extended head-rest yet. I reckon she'll be about 3 before I need to put that on! Hakan recommended me the DuoLogic over the Britax ones, as the Britax are very long seats, but as I said, I have a small baby so unless your LO is also dinky, I can't see it being a problem
It's a comfortable and well-made seat. The thing that swung it for me (which may seem trivial to others

) is that you can fit it equally easily with Isofix or a seatbelt. At the time we bought it, our car didn't have Isofix but my Mum's did. Although my Mum has her own carseat, LO is happier in her new one, and being able to use the Isofix in Mum's car to just click it in was brilliant. Our new car has Isofix too, but I know that if for whatever reason the seat has to go in a car without it, I can do that too, and it takes pretty much the same amount of time
I can appreciate that if you're never intending on moving the seat, this reason can seem pretty crappy
