I am planning on de-cat and manifold myself, so I am sure I will flood the forum with videos after, lol...
With standard engine parts, this is how mine sounds...
No drone on motorway at all. It's almost silent below VTEC (measured at 84.1db at Donnington below 6k rpm) Over 6k it can get you into trouble as you can hear, lol...
Below is a bit of a comparison, the 06&R is equally as loud above 6k as the Spoon N1 with de-cat and spoon manifold, but near silent below 6k in comparison. The sound above 6k is very very high pitched and piercing, the spoon being far more BOOMY throughout the whole rev range.
Mine: Regu06&R (fun starts and 1:30)
Viggen:Spoon N1 (again, fun starts and 1:30 lol)
I am always getting poked fun at when people ask me to rev my car because its so quiet, lol, but when you drive past them on the motorway in VTEC, it usually wipes the smile off their face and turns to an open mouth, lol.
The general consensus is that the 06&R sounds like a fighter Jet above 6k and standard below...
Exhausts are all about de-restriction, a straight through will always give you more power/volume. The 06&R is meant to be more restrictive than most because of its silencing structure, but those that have one with the car on KPRO will tell you it is just as good as any other exhaust for gains. Mikegsi had one I am sure and he loved it.
Plus, it's one of the best looking exhausts out there, the build quality and the welds are a work of art:
Power on the DC5 is difficult, you need to get less restriction which is difficult on a car that isn't much restricted to start with!
At the end of the day, you need to re-map it for the best gains along with a quality manifold, intake and exhaust.