Are new aluminum radiators better?

Aluminum radiators do not cool better than original types, the only thing aluminum does better is to take weight off the car. Sure they will work, and since they are new they may last longer, but there is nothing better than a recored and restored original, that is my opinion and i am sure others will disagree, but I listen to the experts like Bob at Glen-Ray Radiator who does it for a living. Of course an aluminum radiator is going to be much cheaper though.

Aluminum is actually far better at thermal transfer than brass.

Brass vs. Aluminum: Radiator Thermal Properties

OP, run aluminum if you're not on the OE/Resto kick.
And a good sacrificial anode won't hurt, either.