i think this looks beter than the hks dual dragger ( i think the tips look better than the hks), of course its not the actual n1 can but has similar looks. hks dragger is in the quiet category of exhausts so i would imagine this is way quieter than my gt-spec because it has smaller diamter piping, i will also plan to leave the baffles on. i also think a big huge can in the back of a car attracts more attention ( i admit big ass canisters does have some rice in it), than small dual canisters (which makes the car look like it just has a modified tip). i just want my back end to look nice, i dont really want peforeman out of the exhaust, my perfomance and sound will come off of the downpipe and electronic cut off.
there might have to be some fabrication done such as hanging the exhaust higher, and modifying the exhaust opening on the bumper, but after all is done (setup, fabrication) i think it would look decent and efficient. just to let you kno, if your a fan of the original abflug s900, it has dual tips. i also think dual exhaust systems/tips are more hardcore drag.
now for the main point, how do you know its a knock-off? apexi does make N1 duals, for liek rx7's and 240's for sure, i dont see why not make a real one for the supra.