My Britax Marathons have likely expired so I need new car seats. We have several years left on our Britax Frontiers so my plan is to move my 4.5 year old to the Frontier and put my 8 year old in a booster. My 8 year old is small for his age (48" and 54 lbs). I'd like to use a high back booster in our minivan. I'm newly pregnant and if things go well, I'll need to fit 3 car seats across in my car. It probably makes sense to put DS1 in a regular booster seat in my car.

I'm looking for recommendations for both high back and regular booster seats. What made you choose your seat over other brands? What do you like/not like about it?

Thanks!