I just upgraded to a Koyo Aluminum 2 Row Rad, Nismo Rad Cap, Nismo lower temp thermostat, new OEM waterpump and Flex-a-lite 220 fans with thermo switch. They work amazing. Looks hot, removed my overheating issues. The aluminum rads are lighter than the stock ones, there's also copper koyo rads available but they are way heavier, almost triple the weight. As for cooling efficiency, I've heard that the alum and copper ones are basically the same, but slightly better for the copper ones. The copper conducts heat better. It's also like $200-300 cheaper.