I am not sure who has checked out car seats, but in this article: http://www.ratedbymom.com/2011/08/diono/
it says the Radian is going to have a name change. Before the name change, the old Radians will go on sale. They are usually around $200. I don't know if it also goes for Canadian seats too? But these seats are good from 5-65, 5-80 or 5-100lbs.
These are good practical seats. I bought one when we lived in USA. It folds somewhat flat and can be used on a plane. We always bring it with us when we fly to USA. BUT as convenient as it seems, it is no where near perfect. We have tried it in many cars and it only fits in some. It just won't safely install in many cars. So if you are considering it, make sure you test drive it first. Also because it is a rfing seat that has a super high weight limit (I think 40 lbs rfing and the ffing is stated above), it is nearly impossible to fit in the back seat rfing in many cars because it is so long. But it is very narrow and can fit 3 across in the back seat.