Carseat help

So we have the Britax Advocate and so far both my H and I hate it. It's so big and its so hard to get Ava in and out of it. It's a pain to move it from car to car too.

So I'm looking for another seat that we can us in the other vehicle. Something that is also a convertible and can be rear facing, and something not too bulky so we can take it in and out of the car. Also something way cheaper than the Britax. We won't be using it very often. Any suggestions?

Thanks!