Since I have both the SL55 with TVT tubes and devil horns and the NW Dual CAI, I can give you a couple of performance comparisons....

I was running the stock SL55 intake on the Aero for quite a while and it did very good..... I got the Aero down to 12.06sec @ 114mph last year with that and my other mods.... could not really hear the SC whine with this setup.......

Then NW came out with the Dual CAI and I swtiched over..... I got to try it at the track at the end of the season and ran 11.96sec @ 113.9 on back to back runs... .... you can hear the SC whine with this setup.....

I installed the SL55 with TVT tubes and NW devil horns on the stock SSB and ran a 12.8sec @ 109.7mph two weeks ago.... I never ran it stock at the track so cant tell you what improvement it was... no SC whine, but definite increase in power.....

I like them both. The NW Dual is a better performer, from my expierence, but you will be happy with the SL55 intake.... you can always add the TVT tubes and devil horns later....(like I did).....