Budget: Toddler, Cosco

Convertible Seats: Cosco Scenera Vs. Evenflo Chase

I need to buy two carseats (for my 3 year old so that the britax marathon can be used by my 1 year old). I don't have the $ to buy two additional marathons so I am looking for safety, value, and comfort. Anyone out there have had experience with these two models mentioned? thanks so much!