A 1200kg "sports" hatch will not ride as well as 1700kg V8 sedan, the added weight of the car helps to keep the car settled. From your description I'm not sure what you want exactly - good stable handling at high speeds, or stiffer for corners? Its near on impossible to have both.
As I may of pointed out that 180 is fine in this car and 210 is possible, it's only the damping that's lacking.
Stability is the whole point it sits well cornering in tight stuff no need for springs or sway bars, I am not racing you know just plodding along with care and attention, the 2.4L loves to sit on 120km/h and with a tickle it will bus up to 180 as easy as pie it's no sweat at all it loves it, that were driving this car is all at, this is it's sweet spot, just taking it easy 120 to 180. but damping can be better and when you start to get up it it's only the lack of good damping that rears up as crap, take it as a review of the cars capability's .
A great car let down by lack of rubbish shocks, all would be fine for some base model Lancer driver to just plod around in total ignorance, but not what a GSR should be and it's only the lack of damping that lets the car down.
Only a idiot would lower the GSR, some city slicker trying to show off trendy crap, but I know driving all over Australia that the std springs are just fine.
And I am not some novice driver as I have raced cars and bikes driven trucks and I am retired so 180 is not big deal on the NT highway at all, it's now 130 km/h more cars are on it now, but hey if you feel you should slow down in a situation you can do that you know and if you are doing 210km/h it had disc brakes front and rear that can was away speed very quickly the brakes are great on it, it's not a HK Holden with drum brakes all round and rag tyres, and the highway is as wide as and spot on, not like the crap we drove in the 1960's and 70's that were everywhere just a one lane highway where you got 2 wheels of on the dirt when another car came the other way, not to mention we drove across bridges with trucks passing by the other way that are now only one way and that's how useless drivers are nowadays they would freak out, ha ha talk about pathetic ! and a lot of people in them days sat on 80mph on them roads in QLD and the cops were not worried about such at all.
People are paranoid about speed nowadays because of the Socialist Marxist agenda that everyone is seen as the lowest denominator and everyone is equal, well fact is no one is equal and not everyone is the lowest denominator.
I sit within the speed limits in town city big city highway because that is best rule to follow, I don't go doing stupid things like most ignorant city people do when cars are merging on to the highway or sit to close like many fools do, or sit in the wrong lane hogging the road, boy when are we going to get speed limits like Europe has faster you go, then you head on out to the far lane, it's just logical but Australians are f ing to stupid to understand reality nowadays.