We get calls every day from BMW owners that have worn out their original run-flat tires and are on the fence about keeping the run-flat tires or going to a non-run-flat.
My best recommendation is to base your decision on where you drive. Many people commute in areas that are well populated and would have plenty of spots to pull over and wait for a tow in the event of a flat, but if your commute is more "rural" you could find yourself inconvenienced by a long wait in a potentially dangerous spot. In those situations, I'd recommend you stick with run-flat tires so you can drive to a safe spot to wait for help.
We have had many people switch to non-run-flat tires and make some kind of "backup plan" in the event of a flat tire; like adding towing coverage to their car insurance, joining AAA, or buying a spare wheel and tire. Most cars that are equipped with run-flat tires as Original Equipment do not have a spare tire (full-size or space-saver) in the trunk. Many do not even have a recess to accept one so options can be limited. Continental tire offers the ContiComfortKit as an alternative to a full-size spare that can help in the event of a punctured tire;
As long as the sidewall is intact, the Continental sealant can buy you some time to get the car to a shop or at least to somewhere you can be picked up.
Non-run-flat tires can normally be found in all-season compounds to offer you more durablility and a quieter ride. Even if your car never sees snow, the all-season compounds are somewhat less "sticky" which improves durablity. Many of my customers have switched to the Bridgestone Potenza RE960AS Pole Position or the Michelin Pilot Sport AS Plus with great results.
I've done both tires on BMW and Lexus applications with great feedback, so they are worth considering!