My first mod on the R was the Milltek cat-back exhaust!
Noise wise, I think the exhaust is great and really makes the car sound as powerful as it should! I have a few vids on my YouTube channel (though I'm sure you've already heard the exhaust in plenty of vids).
From inside the car, it does not make a drone (I did the flapper mod on the R and THAT makes a drone) and is very livable, but of course louder than stock. If you do a lot of city driving, the flap is open in 2nd and is a tad too loud, but otherwise 99% of the time it is awesome.
As for the resonated sound, wait two more years and I'll record it for you!
The ONLY thing I do not like with the Milltek so far is the build quality. My pipes have suffered big time and the ceramic black tips will look worse with time. I have notified Milltek but no answer on their part.
First the inside wore:
And here is what it looks like now:
So keep this in mind when choosing an exhaust!