I have cargraphic stage 1 quiet (I think I have the only one they ve ever made..). I am happy overall with the exhaust and it made a very noticeable difference when I switched (+ 50hp with exhaust+ ICs on the dyno). But consider this; I took the car on the track at bedford and they stopped me after 4-5 laps because my car under throttle was setting off every noise sensor on the track. Overall I would say that on the inside the noise level is acceptable, only problem is some resonance at 2.5k rpms. On the outside though, all hell breaks loose when I floor it.
I don't see why anybody would get a louder version than that. I ve also heard the cg version 2 and it was too loud for my taste. If anything I might try later on switch to a more quiet exhaust. I am planning to try to listen to the sportec exhaust with the electronic flaps.