DS is 3.5yrs, 42lbs, 44" with a size 5 shirt. I want a seat that he can comfortably sleep in for a long period of time. We've tried the Frontier, Nautilus, SureRide, Maestro & MySize 65 (the My Size is at a nice recline but is too narrow for him to sit without rounding his shoulders). The head slump is pretty bad in all of them. Is there another seat I can check out? I prefer something with a low profile like the Frontier.