Got a huge puncture and rendered tire useless right away. Forget the 50 miles. Couldn't move an inch without damage to wheels. happened on a Sat and had to wait til Mon for dealership to open so can use my extra tire coverage plan. Why no spare is beyond me.
Negligible. P7 run flats weigh about 24lbs each and comparable potenzas in normal tires weigh 26lbs each in the same size. Add in a spare wheel and you're talking maybe 60lbs saved with run flats. It's probably more a packaging issue (space in the trunk) more than anything else. I doubt anyone can feel 60lbs while driving. At the track, maybe but not seat of the pants.