Elaborating more on sound - this is what i wrote in other thread:
The best noise it makes on a cold start - raspy rally car type noise
When hot it gets a bit quieter but, i would still call it a bit raspy. This is in my opinion signature mark of milltek - all of their exhaust i hear was a raspy note and i love that. Not boomy, although on low revs it sound little bit boomy on neutral / stable throttle but when you accelerate it gets lovely raspy
Milltek is very well design exhaust that will give you lot of fun when driving in the town, witrh low revs (where intake is quiet) thanks to that even normal, slow driving is fun ( on standard exhaust is just boring).
When revving high on other hand is still loud, but not stupid loud.
I just fitted HKS RSK and i'm upset as intake is noisier when on vtec than exhaust... i love the Milltek that much
Oh - and motorways are ok with it - around 4k revs, stable throttle and it's sound like a sports car, but it doesn't annoy you.
One thing has to be said - when you fit this after standard it will surprise you how loud it is... after time you will get used to it and it becomes normal, but first day will be like "What the f*** they were saying on the forum?! quiet!!??"
It's not quiet exhaust, it will turn heads in town, but it won't make you feel tired.