A little late to this thread. What do you like about a run flat?
To me? They are heavy and expensive, and what are they saving you?
With a run flat, you can travel "up to" 5o miles. 50 miles to where? To the corner gas station? Do they have any 315/35/20's Dunlop run flats on the rack? NO.
Burned through 2 sets of run flats in about 8 months per set.
Check out tirerack. If you look at the weight of each tire? Front runflat is 7 pounds heavier, per tire than an all season. Rear? 8 pounds.
I put Continental DSW on my X5. Going into my 3rd summer and lots of tread left.
Car is totally different with 30 pounds of lighter tires.