Yes, I am comparing a copper/brass radiator (which I have one in #20 as an oem replacement; forgot the brand though) and unless it has a different design and/or far more surface area (i.e. FPI), aluminum will not be as efficient (has about 62% of the heat trasfer rate of copper)...Weight, sure aluminum is lighter (about 31% the weight of copper), BUT there isn't that much material to make a huge difference, considering and there's probably more liquid weight inside than the entire weight of the radiator (I'm sure you've picked up an empty radiator on these to see how light they are).
Anyhow, only reason I bring this up is I'm curious as to why it needs to be aluminum and/or if the OP was aware of this, as he mentioned direct fit and therefore is constrained to the same rows/size as oem, which really wouldn't give him a lot of benefit and especially considering the possible cost difference...It does look nice though (aluminum) and I'm sure it'll work fine, as these cars don't suffer many heating issues, provided everything is up to par.