After much investigation and studying...this is the seat we have decided upon...
The Radian XT
Landen is a mere inch and a few pounds away from outgrowing his Roundabout. He has been in it since 10 months or so, and I figure the Radian with its 80 limit will be the last seat we ever buy and since he will be in it until he hits the 80lb benchmark or the height, then I don't feel bad forking over the dough to have this one.
http://www.hipmonkey.com/car-seats/s.../prod_204.html