We had an 4 stage all in 1 that we lost the converter's to which caused us to buy this car seat for my toddler. He loves the increase in room size in this seat from his own one and the fact that it feels more like a "big boy" seat. Ease of Installation Very easy to install in multiple cars using the seat belt install or using the harness system. We have been using the seat belts as it seams easier to move from seat to seat when necessary that way. Child's Comfort My child absolutely love the more openness to this seat compared to the previous one he had used and has much more leg room now Support and Safety This seat seems very safe and it can work well in any seat thanks to the use of either seat belt system or harness system to lock it in. Ease of Use It does take a few minutes to change from seat to seat, however it doesn't seem to take any longer than other car seats we have had (and actually seems a little quicker). Design I like the head protection and the design both emphasizes comfort while at the same time not skimping on safety. Durability While we have only had this seat for a couple months, so far its held up to the typical hard use of a 4 year old toddler.