The new ones come with 2 seat fabrics, one to use until 18 months and one past 18 months. Ella is a biggish 6 months and already looks too big in hers and I have the straps as long as they will go already (I have the extenders, but the are only about 10cm long) so she will outgrow it fairly soon.
IMO they are not brilliant for older babies and toddlers - they can't sit upright when parent facing only when facing out and even then they can't really sit up in the same way that they would in a buggy as the bum bit of the seat isn't deep enough so they still end up slouching down.
I wouldn't buy one again now, knowing what I know (if that makes sense)
