Even if I go up the the better model with the "moveable" head wings it is supposed to be very hard to install (that's in quote because it seems that that are all sorts of issues with those, too). We had a very hard to install car seat once already and don't want to deal with that again. Even the Car Seat Lady says that all the Diono Radians are a bear to install...There are also a zillion complaints about Diono customer support. I've only had to call about a car seat once, and was sent a complimentary replacement foam piece quickly and at no charge to me. That does not seem to be the case with Diono.
So, you Diono Radian owners, have you had a hard time installing this? We'd use it rear facing first (and reviews say it has a very deep recline that interferes with the seat in front of the car seat) and then forward facing and then as a booster. There seem to be critiques of every single stage and what is mentioned is certainly way more bothersome than any car seat I have ever owned.