I'm encouraged by what we do know. The interior looks terrific as far as design, materials and amenities. My experience with the GTO would indicate that Holden puts a lot of thought and a lot of cool little details in their interiors, and that the materials are very good. You'll probably still find some cheap plastic bits, but they're forgivable at the price point. The infotainment system won the CES award for car audio last year, which is good because the sound system in the GTO was a major weakness.
GM says they tuned the suspension differently than the Commodore for an American audience, meaning they softened it up a bit. That's probably wise, because a car on 19" wheels and 40 and 35 sidewall ratio tires is going to be stiff. The GTO had a great ride...very smooth and very solid. Great balance, easy to toss around, very willing. I expect the SS will follow suit. Expect dual personalities:
Personality #1) Smooth, quiet, civilized sedan with a nice cabin, happy to shuttle the kids off to school or pick up the dry cleaning.
Personality #2) Godzilla.
Personality #1 is the default.To select Personailty #2, depress right foot a quarter inch.
Performance wise, you guys are in for a treat. Again, based on the GTO experience, you will not be able to stay out of the throttle. Intoxicating power and on-demand speed in pretty much every gear. Very few regular cars on the road will be able to pass you without permission. Whatever little shortcomings you may feel the exterior design has will be completely overcome in your mind on the drive from the dealership to your home.
My guess is that the SS will be a very capable mix of refinement, sophistication and technology. I don't think "perfect" actually exists under $100k.