If "quiet" cruise is what you want, Corsa is pretty much the only option. But don't get a catless downpipe. There really are not many advantages.
With that said, no turboback is quiet on these cars.
If I had to do it all over again, here is what I would do, and I have no scientific evidence to support my theory, but the Y pipe messes the sound up and added noise all in the wrong place.
Buy a single exit tame exhaust like the Q300 (comes out the right side), and be done with it.
The Q300 DUAL and SINGLE do not sound the same, and it's b/c of the Y pipe. If you actually look at any other performance car, none of them do the Y crap. They use a single large muffler section with piping coming out on each end-- much like the GR hatches.
To this day, the absolute best muffler (exhaust) I have heard is the APexi WS2. It in incredible sounding, super aggressive and mean, but really quiet, when you want it to be. It's simply the best of both worlds. Nothing even comes close IMO.
The Corsa is a wannabe Apexi, and the tone is actually pretty similar, but Apexi is definitely quieter and sounds way way better on ELH.
I am strongly considering buying the Invidia 300, chopping the muffler off, and buying the Apexi WS2 muffler. It's that good sounding, all while being drone free at any rpm.
Listen here, but of course, the video does not do justice.
Apexi Noir 2005 Saab 9-2x Aero - YouTube
Subaru wrx apexi exhaust - YouTube
I like the sound catted and with a resonator. It can get way too raspy if you go catless and no resonator, and really noticed once you go ELH.