Okay ladies at what age will you start letting you children sit in one of these? My husband was asking me if we could change my 4 year old car seat since these are less bulky than actual car seats and my car is a bit small. Don’t get me wrong I’m in no hurry of changing her car seat I think both car seats fit okay but when we do travel it can get a bit cramped up with our bags and he just wants a bit of more room if that makes any sense. Again I’m in no hurry, just wondering what would be a good age, Since I am very strict on car seats wanted to get see some of your opinions.