The dunlop run flats ride nicely. The bridgestone runflats are firmer. I've owned BMW's and prefer a firm - I can feel the actual pavement - ride.
Now, everyone harps about getting rid of runflats. There's an obvious compromise and the most important one IMO is safety. You will NEVER catch me, nor my family changing a tire by the side of the road. It's unsafe and just a PITA. For those with a family, and who do not want to change their own tire/wheel in the event of a flat, the runflats are an excellent option.
Do they weigh more? Ride a bit harsher? Cost a bit more? Sure, but they are also a welcome technology that I'm happy with.
I just got done buying a set of Bridgestone take-off's from a bimmer owner and switching from the Dunlops to the Bridgestone's caused bit of increased harshness. My first reaction was, hey I like how communicative these tires are - not a big deal to me at all. However I'm more sport oriented and my wife has NOT noticed a difference. Win win in my book.
Mitchell Phillipi, CCA#189329
'11M3 ZCP, '11X5d