I think it really comes down to the dynamics of your family. I'm a baby carrier and I still carry my baby in the sling a lot of the time. But my oldest has major kicking and screaming meltdowns and I can't deal with him safely with the baby in the sling. So I needed somewhere to sit the baby, then another somewhere to strap the thrashing toddler while I retreat from our outing and get home again! Now my baby is getting older he likes sitting in the pram too so for longer outings, like wandering around the zoo, they both enjoy having somewhere to sit.