I can talk cause ive been through 2 exshaust sys. and i had the the greddy evo slaped on when i first bought my car now i have the apexn1 and its pretty good lot more noticable throttle response then the last not as loud but i think thats because i onlly have a cx stock motor with a akimoto intake . It got nice sound though i think. its just that if your car is lowered it scrapes the us spec speed bumps heh! it does so i raised the car like a inch. Its a better i think then the greddy. ive seen alot of people switch the the n1s and apex is alot better turst me you will notice a differne in flow it feel alot freeer. if you know what i mean. The better your can breath the better.