Hey, long time no see, eh?!
Isn't that Rspec has more stiff suspension than "regular" G80? I never had that feeling of driving a boat, lol ...my '15 5.0 was lowered, so the handling was actually better, more firm and now the '18 G80 sport has an adaptive suspension, it also feels good, I don't even think about trying to "improve it".
I'm glad I had a chance to keep and drive G70 3.3 for a week, so I'm pretty sure I won't be getting one in ~16 months once my lease is up. Even though, we don't have a small kids anymore (thank God!) but still, there isn't room to sit comfortably, behind the driver's seat, head rest is way too far back, I can't rest my head on it as I would in G80 and the trunk? LOL ....after I put 2 tripods, 2 monopads and 2 backpacks with my photography gear, the trunk was filled in ~80%! I know it's a smaller car than G80, but those 3 things will be a deal breaker for me. So, I'll be getting another G80 sport (like '20 leftovers) or the new design '21 G80
I'm not sure what suspension was in 3.3 loaner, but I had the feeling that my G80 sport's was better.