if you want the dual n1 i say just go ahead and get it, even though everyone and their mothers has one now <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt='
'> . about 6 months ago i was in the same position as you, i had just a short ram intake and i was looking for an exhaust that wouldn't kill my torque. anyway i bit the bullet and bought the dual n1 and installed both that and my cold air extension (which had been sitting around for the winter) at the same time. i did feel a liiittle bit of torque loss, but it was barely noticeable, and the gains in the higher rpm's are more than enough to make up for it IMHO, now i can pass people in 5th on the highway! <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt='
'>
i don't have any experience with the other exhausts, but if you are still worried about torque loss, just go w/something quality like the 5zigen.