X5 30i suspension dampening harshness

Hi,
I enjoy the stiff suspension, great for cornering and general handling but the wife has a bad back and always complains about the harsh suspension.

I know this topic has been discussed before and people are saying that changing the Run Flats to non run flats can improve the dampening harshness.
But if I actually don't want to do this and the fact that I drove an X6 and that harshness is not there (as much)
Just wondering if anyone has actually changed the struts/shocks, springs for after market ones and found difference in the dampening ?

I would be interested to know of anyone that has done it and the brand that they may have used

Thanks

X5s are designed with jarring suspensions in mind thats how they get the amazing on-road performance. You can do something to help alleviate that, by A) changing the way the car is in contact with the road, or B) improve how the vehicle responds to the road.

The best option, is probably A.

Get some smaller wheels, if your running 19's or bigger.
Put on some non-rft (sidewalls are softer on then rfts)

B
try to find some softer dampers, or replace with air suspension parts.