My son is has been riding a XS Norco Storm 27.5 in the local MTB program that fits him well. He needs a bike of his own and the Rocky Mountain Growler in XXS and XS are available used locally. Would this be too beefy a bike for a kid who's still building riding strength? I feel the plus tires would help him be more confident over rough terrain but the rolling resistance/weight would generally slow him down which is not ideal for encouraging a young rider. Any thoughts on whether a 27.5 plus bike is too much for a kid just getting into the sport?