We know it. It's a real bummer when your little peanut grows too big for the infant car seat. Oh, we can sing the praises of that cute little bucket seat. So light, so easy, snapping on to the stroller frame. But the convertible seats are different. And you have to understand why: these will protect your little one from 12 months (many can be used for babies as small as 7lbs) to 65 lbs. They need to be strong! They need to be robust. They are infused with so much technology, a SilCo engineer's head would spin.