Quoting I♡C.:" Does he have quite a bit of room to grow as far as rear facing height goes? We're looking to get a taller ... [snip!] ... another year or two if I can find a seat tall enough to do so. I heard the Graco Size4Me is a good one too with a tall shell."
His old seat, the Evenglo Momentum had a tall shell and a 40 lbs RF limit. He had about an inch maybe two before we would have to FF him. The Radian he has a good 3-4 inches before he will have to FF. I'm kind of struggling though, and DH feels the same way, his old seat really cradled him and covered all his sides, like a huge bucket seat. The Radian leaves him really exposed, if it wasn't for the head wings the RXT has I would probably return it. I'm still debating on it now. I want to love the Radian, and do for the most part, but it's just such a huge difference.