Calais V has a Bose system which is quite a bit better than the standard system but not anything like the old 900 watt 19 speaker Harmon Kardon kit in my Chrysler SRT8 which unfortunately was so good it rattled everything loose so I had to turn it up to disguise the parcel shelf rattles lol.
I'm quite intrigued that you think the RSV with 235 kw's is about as quick as your SSV V8 which I guess was the 260 kw V8 one ?
Better gearbox by miles makes quite a difference I reckon.