Better in terms of what? I have the N1, it is not as loud as some of the other exhausts, but does seem loud at times. My friend had the GT spec and it semed to be more quiet with a total different sound. As far as performance, we didnt do any before and after dynos to be able to give you that type of info, but im sure many have.
I have the Apexi GT Spec exhaust and I love it. I assume it is much quieter than the N1 just because the GT spec has a larger muffler and a large resonator. They are both made by Apexi so the quality is going to be the same. You can't really go wrong either way.
The NEW N-1 is available FULLY POLISHED too. I saw and heard one 2 weeks ago.
ALSO, keep in mind that the front flange on the GT Spec necks down to about 2.9" ID, so if you want to take advantage of the larger ID of the rest of the system, you'll need to replace the front flange. I replaced mine with a 3.5" V-band and it worked out nicely.