After doing quite a bit of research I found that all new cars, race cars, exotic cars, rally cars, supercars etc use alloy radiators. Not sure about heat dissipation and corrosion. I read mixed responses. But due to the sheer extra thickness of the alloy radiators (15-25mm) I suppose they can outperform a stock copper one also alloy ones have less chance of corrosion (I may be wrong!)
Coming to leakage of the radiators, the fact that copper cannot be welded and the radiator is full of brass (tubes) and solder (holding the tubes in) which makes an alloy radiator better at least when it comes to welding. Anyway this is all what I gathered but I may be wrong!
Aesthetically they look good as well