okay so after reading that, the Antec one is a bronze rated psu with minimum 82% efficiency whereas NZXT one is a gold rated PSU with minimum 87% efficency.
Antec has multiple 12v rails whereas NZXT has a single 54A rail
the price difference between the two is not much though around 20$ ???
Give that a read as well.
Anyway, they are both pretty close, but the NZXT is overall a little better.