I will firstly explain the title of this thread. I own a  6 Series gran coupe that has run flats on 20 inch alloys, it really was shocking over small pot holes and rough surfaces. I was told it was the run flats, they are the cause and I should loose them. I just changed the springs to Eibach 20/25 springs and 15mm spacers all round. I am still running run flats and can tell you. Wow honestly I have owned and modified a lot  of cars and never experienced such a change simply by changing springs. It really does take bumps and small pot holes as though they are not there. My car has only done 44k miles therefore it is highly unlikely my springs were done. All in all the run flats have nothing to do with the ride in my experience.

Morning Oneel

Sounds like win win with the new springs (1) you get the stance you wanted (2) your ride comfort is improved 😁 Run flats by the nature of the beast and their construction have incredibly stiff side walls to carry the cars weight if they are punctured. So replacing them with non-runflat tyres when the time comes will only help the ride further, my X5 runs 20" rims with non-runflat tyres the ride improves drastically when the 18" Winter tyres are on due to the higher softer sidewall.The 20's look better though and it hasn't snowed in Sussex for years !!

Enjoy your Beemer

Dave