Radian RXT or Frontier CT

[Hemlock]

Which do you recommend? Almost 3 years old (39 inches, 39 pounds), forward facing and space in the vehicle is not a concern (Honda Odyssey with no other car seats)

[Joolsplus2]

Radian is not all that comfy forward facing according to 3 of the kids I had that rode in it. And it makes a terrible booster (http://carseatblog.com/30862/2014-ii...-booster-rank/, not only does IIHS not like it, but it allows a lot of slack to stay in the belt after a child leans forward. And also, it has a 50lb starting weight in booster mode, by then kids are often too tall for it anyway), so you'd only be getting a couple years of harness use out of it. Though it is very low profile and easy to climb into, I found it nice in a car with lots of other kids clambering in and out. Good choice IF you plan on having more kiddos, it has a long expiration date and is stellar for rearfacing.
Frontier is awesome, and now that I re-read the stats, that's a pretty big kiddo so maybe it's a great choice. The 90 model is absolutely flawless to install, it has loads of leg support and booster height. Can be sticky as a booster (belt gets caught in guide allowing shoulder slack), and it's very bulky and harder to buckle, but if you harness to at least 7 and still have that van, I found it to be a great booster in my Ody, where I could adjust the height of the shoulderbelt and the seatback recline, it made my belts work great.
Might also consider the Recaro Performance booster, it's a nice little seat that works well in harness and booster mode, too. http://carseatblog.com/9824/recaro-prosport-review/

[Hemlock]

No more kids for me, so it looks like the Frontier is the winner! Thanks for your help.