My two cents - a combination of both is best. For me, the downfall with dumbbells is that lifting really heavy wts (125 pound +) is not realistic without some real help and when you get that help it is kinda awkward. So, for me, maxing out with wts is easier with a barbell and is also easier on the spotter. And as you get older or start maxing out with wts, injuring the elbow joints is easier with a dumbbell.