The above mentioned brands has the exact same complete range of car seats which in my opinion covers your kid right from infancy till they are big enough for just a simple booster seat.
Below are the list of groups of car seat for kids of different sizes. All the car seats in each group are practically similar.
This group of car seats are for infants up to 13 kg. However the new car seat standard is no longer based on weight but the height of the child so as soon as your child outgrows the tallest harness position, it is time to change the car seat to the next group.
The seat is secured to the car with the car's 3 point seat belt and the child is seat secured to the seat with its 3-point harness.
The good thing about this group of car seats is that you can remove the seat from the car while the baby is still in the car seat. However, securing the seat to the car with the car's 3-point seat belt can be a challenge and it increases the possibility of improper installation.
This group of car seats can be converted from rear facing to front facing when it is appropriate.
It being in the group 0-1 means it is suitable for your child from birth when installed rear facing. When your child is able to lift himself up and has outgrown the lowest harness position, it can then be be installed front facing but it is best to keep the seat rear facing for as long as you possibly can (and if your child is cooperative)
The seat itself is attached to a mounting base that allows the seat to be reclined without having to readjust the car seat belting, which is a good thing. There are other convertibles that requires you to re-belt if adjust the recline angle which is very inconvenient and also increases risk of improper installation.
However, the seat retains its seating position so your child do not actually lean back when the car seat is reclined which is similar to the likes of Maxi Cosi Priori range of car seats. This car seat should last you for quite a while until your child outgrows it.
The seat is secured to the car with the car's adult 3 point retractable seat belt or ISOFIX / Latch Tether combination and the child is seat secured to the seat with its 5-point harness.
This group of car seats are for taller kids that have outgrown the convertibles.
It is practically a booster seat with a high back and 5 point harness for taller kids. The harness and high back can be removed. So if you already have or are going to have this, it will be the last car seat you will ever need for that same child.
The seat is secured to the car with the car's adult 3-point retractable seat belt and the child is secured to the seat with its 5-point harness
These car seats are practically the same as the previous group but without the harness so if you already have one of those and your child has outgrown the tallest harness position, you can remove the harness and buckle and you will have the same thing.
Child is secured to the car with the car's adult 3 point retractable seat belt.
These seat are practically the same as the previous group but without the back rest. So if you have a seat from any of the two previous groups, you can convert them by removing the harness and/or backrest.
This car seat is for kids tall enough that the car's 3 point seat belt does touch their cheeks when seated on this booster.
Child is secured to the car with the car adult 3 point retractable seat belt.