So DS2 will be 4 in June, and I thought we would turn him then (he is currently RF in a Radian XT, not SL). He's 36 lbs and 39". As such, he still fits quite well RF. I *think* DH would like to turn him, but he generally defers to me about carseat stuff. And we're not really getting any flak from anyone about ERF. A few people have been mildly surprised that he is still RF, but no one has been critical about it. The Radian works great RF in the 2nd row of our Mazda 5. So . . . . I'm not sure what to do. Obviously he can't RF forever, and 4 years of RF is great. At the same time, I'm not sure why we *should* turn him FF. Any thoughts from others who have faced this decision?