I have it and absoultuly love it. I have a tallish 3 year old at almost 40inches but shes thing just around 30lbs (now she was 29lbs when we bought it). We were deciding between this and the Britax Marathon as I wanted to harness her as long as I can and I need something airline compatible. The marathon didn't fit right in my car it kinda leaned foward no matter how much we messed with in (professionally installed) and DD undid the harness way too easily
: THe Radian however fit our car like a glove and its rock solid, and DD loves it though I have heard it doesn't in all cars. So I'll reccomend it but I'll also say you need to get what both fits your DC and your car the best.
Deanna

Deanna