G.S.
We have and use Sunshine Kids Radian 65. Although my daughter had clearly outgrown her Graco before she turned 1, we were still using it until her 1st birthday, when we could feel a little safer switching her to forward facing.
We drive an awful, ancient Geo Prizm. To fit the Radian 65 into our car, we really NEEDED to do forward rather than rear-facing (due to the height of the seat back), and we had to install it behind the passenger seat, rather than in the middle (although it is narrow, it might not have easily fit in the middle, and it would not have been easy to secure with its anchors/tethers in our ancient vehicle).
That said - we love it! As does our toddler (now 15 months old). It's easy to remove and install, and it has not simply decided to fold shut on its own! (That would be a serious safety hazard.) I think it's a great seat, and I look forward to taking it with us as we travel to Chicago next week.
I think the biggest concern is the right fit for your child. If you have a wider kid, it might not fit as well for as long as you'd like (narrow car-seat). And while my daughter is really big (between 75th and 90th percentile on the charts), it seems clear to me that she should be able to use this seat until about that 65 pound mark (although, depending on how long that takes, she might be getting to be a big girl, who needs an older kid booster seat -- we'll cross that bridge later.)