The biggest difference between the two car seats is that the EXEC is an All-in-One car seat whereas the RAVA is a true Convertible Car Seat. Convertible Car Seats can be used rear-facing and then convert to forward facing as the child grows. An All-in-One Car Seat, which is the sub-class the EXEC sits in, can also convert from rear-facing to forward-facing but it has the third bonus of turning into a booster seat for an even longer use. Typically, usage capacity is highest with All-in-One seats.