Mine is 3K something rpm for 110kmh. 1.8 manual stock. If 3.5K already reach 120 kmh

Thicker antiroll bars does not mean better. Yes, car don't roll that much but it has to work hand in hand with the spring. Inspira springs are soft, so if roll bar too stiff, the chances of other wheel lifting is more often; which also means less grip during corners and too much weight on one side = flipping over. Even in rally, they do no put the stiffest bar they can find, it depends on the track and the dampers used. Inspira was tuned for msian bumpy roads and unpredictable corners.

Inspira body rolls a lot but almost impossible to lose its tail. A stiffer setup means more sliding around until u put on more grippy tires. So you either do the whole works or don't start. Lancer had a stiffer setup but it loses its tail quite often and oversteers; this is something proton improved on but most drivers do not understand and start changing to stiffer setup like lancer. This is what proton meant when they say they made the car's handling better.

The ride is yours, so you decide.