An update on the Corsa exhaust install... had to get creative to get the car onto ramps, since my low-profile jack didn't go high enough (good thing I had a bunch of wood pieces laying around). As the others, major pita to get the OEM exhaust off the hangers; the back ones gave me the most trouble since there's not alot of room, and the two hangers are facing each other only about 4" apart. For all the DIYers, you might consider picking up a hanger removal plier. The installation of the Corsa was easy compared to the OEM removal, and I would further support the notion of getting an axle-back, if just for the weight savings - the OEM muffler is crazy heavy. The Corsa is of high build quality, and the stainless looks good... the tips look great, but as most note, they're on the small side compared to others. (seen Akropovics lately?) It's not bad though, comes off a bit more 'understated'... similar to my AWEs on the S4 (100mm tips, when many others were going way above).
So I bombed around for half an hour and a few notes on the sound: first the cold start is deep and guttural, almost as deep as my Z06 idle (has that nice raw burble), once it warms, it becomes deathly quiet - about the same as OEM. There's no drone, and if you're out of the gas, I dare say it sounds quieter than stock!
There's a spot ~1800-2300rpm with part throttle, the exhaust and even the mechanical whine just becomes imperceptible, but get to 4k+... the growl becomes prominent - definitely a nice higher-pitched, european-exotic tone. This is in stark contrast to my B6 S4 I had a few years back - with 200cell APR downpipes and AWE cat-back, that car was the closest thing to a teutonic version of a big-bore, american muscle car. (with the 40 valves adding a decidedly unique sound up top - it wasn't M3 level, but it revved to 7900) As most exhaust, I expect this system to get a bit louder once the carbon deposits build up, but this exhaust has the uncanny characteristics of being either hushed or rowdy, all dependent on your your level of throttle aggression - it's like having the NPP (valve-tronic) of the 'vette.