Honestly, you won't notice the difference, it's only 10mm (1cm). I personally regard these two exhausts as being essentially equal.

 

Hey thanks guys
I went with the Apexi WS2 and its great so thanks again!

 

amen on the ws2. just got mine put on great sound and look. me gusta me gusta

 

Ok so I got it and I like it but it's kinda quiet. I'm going to get a header and a high flow cat. Will that stuff make it louder?

 

probably, but the biggest difference is the catback. You're not gonna want "loud" in about 3 months, it gets annoying quick lol

but a header is a very good investment, high flow cat is fine too, they'll go well with your new catback

 

A header and high flow cat will make it just a tiny bit louder, but the most difference will be in the tone. It should sound a lot more aggressive with those mods.

As Flip said, I don't think louder is really what you want. Loud gets annoying REAL fast, whether it be due to cops noticing you more, or that loud exhausts tend to drone out your stereo while driving at highway speeds.