I'm a capsule fan, particularly good in winter as you can bunny rug them once they're strapped in (inside where it's warm) whereas with a seat you have to unwrap them in the cold to strap them in. Also good not having to wake them up to get them out of the car. Also good if you just need to pop into a shop for five minutes, you can just carry the whole thing in!

In fact, I wish they made the capsules a bit bigger so you could use them for a few more months!!
:-)