Travel systems are pants IMHO.
The car seat is there to keep Jnr safe in the car, the child should only be in them or an hour (2 at the most) at a time.
An infant should be laid flat not crunched up in a car seat when being pushed around the shops etc.
That is why we went for the Britax Iso-fix and a Jane powertrak 360, the car seat for in the car, the pram when not in the car!