My son is 23 months, and is around 37 inches tall and weighs around 37 or 38 pounds. So, I too am looking for a booster. He has been in the Britax Roundabout (since birth) and we love it! It sounds like you recommend that kids stay in a 5-point harness until age 4 -- why is that? You had previously recommended the Britax Marathon or Britax Husky/SuperElite for large toddlers. What about the new Graco TurboBooster? Any help would be greatly appreciated! We'll probably buy two - one for each car. Thanks.