The bulkhead or the drag link for the steering will take on more damage with the aluminum arms, however i have just the aluminum upper arms on mine, i have beaten the living hell out of that genesis, i broke the drag link ( steering link) once, replaced that with aluminum also, and i also have a cracked bulk head but i epoxied it and it has held . Heck i even busted the wheel axle right in half sending one of the front tires flying on a high speed roll over and yet the arms held up. overall i feel the truck is more durable with the aluminum arms even though the damage will start occurring elsewhere.