The GXP will sound a million times nicer than the GT.

I think that they will make the gxp sound really mean!
unfair!

Hope so. Might encourage them to make the whole range actually sound like a V8.
The HSV systems in AU sound almost identical to the standard VE range, even with the engine difference.
The HSV range gets mandrel bent stainless dual exhaust systems with better headers but isn't really much "better" or "meaner" at all.
Still very soft.