DD (3.4) is in the Two Way Elite. DS (5mo) is in a Recaro infant seat. In my head I was thinking that DS will outgrow the Recaro around the same time DD outgrows the ERF and so she will go into a HBB at the same time he moves into the TWE.
However, tall as DD is (top centile line), she still has masses of growing room in her seat, and is a skinny minny. I reckon she will have an extra year in the seat after DS would start using it.
They are pricey, but (imo) worth it, but for a years worth of use?
I dont know what to do (though of course I do have some time!)