Forward-facing harnessed seats provide a good level of protection for kids who have outgrown rear-facing. A 5-point harness secures a child in five places: both shoulders, both hips and the crotch. Convertible carseats have maximum weight limits of 40 lbs. to 80 lbs. Many children outgrow the lower maximum weight limits—these seats typically look smaller too—before an age where they are mature enough for a belt positioning booster. Fortunately, there are many forward-facing seats in all price ranges now with harnesses that go to a higher weight limit. It's important not to move a child to a 3-point lap/shoulder vehicle belt too early: an immature child will not sit in a seat belt properly and may be seriously injured in a crash. He's also a distraction to the driver. Let a kid be a kid and leave him in a harness until he can sit properly in a seat belt and booster—around age 5.