I'm not tooo much use, we've got two convertible ones - I think they're both Safe 'n Sound brand. Have had no troubles with them. Got them both on sale, that really was the deciding factor for me, I couldn't spend much money.

If money wasn't an issue, I would have looked at something like the 'turn-a-tot' (think that's what it's called), to make getting kids out heaps easier, and for the older one, one of the seats that goes up to 26kg. But yeah, the Safe 'n Sound ones have been fine for us, not too hard to use.