The Britax One4Life Slim ClickTight All-in-One car seat has a mile-long list of features: a robust ClickTight belt-tensioning lockoff panel, a top harness slot height higher than most harness-to-booster seats, a top shoulder belt guide higher than most dedicated belt-positioning booster seats, flame retardant-free machine washable fabrics, and more! What else could we talk about in our review? Plenty.

Boasting tall harness slots, a narrowness that works in many 3-across situations, a robust ClickTight installation system, and naturally flame-retardant fabrics that are machine wash- and dryable, the Britax Poplar and Poplar S convertible carseats seem to be perfect. But nothing is that perfect, right?