DS is 7.5 and asking for a booster. I figured I'd get him one and start training him this summer and then put the Frontier back in if we go on a long trip. What are the best boosters out there now? I'm looking at the Kidfit, Recaro Performance, and Britax Parkway SGL. Thoughts or suggestions? He sits in a captains chair in my vehicle and a bench seat in DH's truck.