The only other point is that the LATCH system is limited at 65lbs for rear facing, which my boys and the Diono RXT together will likely exceed fairly soon so will have to switch to seatbelt to attach the seats to the car.
If your RXT was manufactured before March 2014 Diono certifies use of the the SuperLatch connectors to the maximum combined weight rating for the seat so long as the vehicle is a 2005 or newer. I would say it is a "parental decision" to take up Diono on their weight limits, but car seat manufacturers are typically very conservative with their limits and recommendations since they carry a lot of liability.
I have 2 Radian RXTs, one currently forward facing and one rear facing. I found that I had*remove the second row seat's headrest to fit the seat forward facing by removing the plastic access panel on the back of the*seat, popping off a metal retaining ring, and disconnecting the stow and go cable. I use Diono's own seat protectors with both seats to protect the leather.