I really don't know that much about radiators, but have just been under the impression (since I've seen so many) that aluminum must be better, maybe more expensive, but better performing. Yet I look at the price of a Walker, and they're very close in price to the cost of an aluminum one, so now I'm confused, I figured traditional might be cheaper, pay a few hundred more for the aluminum and get better performance, but if they're close to the same price, why buy one over the other?