How is the strut bars "more or less the same" ????!!
Does strut bars modify camber, toe, or caster of a wheel ? NO!
If no, how it help "steering responsiveness" 
The job of the strut bar is too reduce/maintain chassis flex during centrifugal load , thus providing a more rigid chassis to let suspension do it job.
Same thing for struct brace, lower body brace, etc etc. To avoid chassis/body flex.
ess530i : In your case, the only way to improve you comfort are 1. reduce your rear struts thickness 2. softer spring/damper
or yet, ask your passenger to ride a cab. LOL
This might sound weird, have you try soft+medium setting for you rear ? Yes, 1 side is softer, the other side is medium (or hard). Giving more flex to your anti-roll bar will help comfort.
Front : stiff-stiff
Rear: medium-soft ( or hard-soft )
How thick is your rear bar ? how thick is the ori ?
