I own a '06 Pontiac GTO that I've upgraded the suspension to just below true race track stiffness. I used to road rally and autocross and do like a good suspension, even if it is stiff. These GTO's had all kinds of problems with their suspension as supplied by GM and needed
aftermarket stuff to be what they should have been when built. Problems that included tires rubbing against the front struts and blowing out due to soft rubber bushings. Plus strut bushings that were shot when delivered or soon there after. The '06 GTO's also had struts and shocks that leaked all their oil due to screwup at the maker. A long list of problems that doesn't have to be listed here on the Genesis forum. I went one more step beyond normal road ride quality with my Goat and went with extra firm stuff - replaced nearly every bushing with urethane bushings plus scraped the springs, front and rear struts/shocks and replaced them all with special stuff from Pedders.
I bring this up because while I do like firm suspensions, when pushing a car to the limit, that's out of place in the Genesis.
The Genesis that my wife and I just bought has a decent ride on most roads, but does have some strange behavior on some roads due to what I think is mostly caused by incorrect shock valving. The car isn't really all that bad normally, but isn't top notch either. When on the wrong kind of road it is rather suprising in it's unsettled nature. The car is no where near as bad as the XG350 that we once owned. (Our Genesis is our 3rd Hyundai) That XG350 had
Buick Roadmaster-like suspension. It was your father's
Buick. Very soft and underdampened and with lots of leaning on turns. Great car overall, but really needed lots of extra sway bar diameter and better shocks.
It seems to me that the Genesis is nearly correct overall, but the shocks//struts are unbalanced front to rear (allows pitching) plus both ends allow too quick return to steady state ride height after a bump. The car suspension is quite stiff on impact with a bump (up) but then soft (underdampened) as the car returns to normal height. You get the feeling that you are bouncing up into the air while you are just returning to steady state. Plus the front and rear are reacting at different recovery rates gives some strange pitching motions to the car. I think the rear shocks could be the ones that are too stiff/too soft.
But I need more time in the car to be sure - if the wife will ever let me drive it, that is. She happy with the car as is since she's driving mostly on car choked S. CA freeways.
I don't know if the settings can be tweaked in software - aren't the Genesis shocks computer controlled and adjustable? To me, I'd like to see some experiments with balancing the rear to the front so that both ends return to steady state together vs. acting like they are on two different cars. Maybe get Hyundai to hire Lotus to tune the suspension. That's something that they are known for and could be a selling point too.
Just my $0.02.