TBH I have never used Runflats and the car I am about to pick up does not have em on it. I had a look on mytyre website and found that if your going for premium tyres the difference in cost is only around £20-£30 per corner. Although I am used to running a car with 215 width so tyres were always costly. IMHO I think its a fair price to pay I would rather not have the spare or have to use that tyre weld crap which renders a repairable tyre almost unusable. That said im unsure of the laws regarding runflats I think I read that you cannot have them repaired for whatever reason. The added benefit of then is that if you get a puncture in the middle of the motorway you just keep driving no faffing about. I think to say if you have a flat your not gonna drive it isnt the most intelligent statement(no offence intended mate0) of course you wont, but you may pick up the puncture on the move. A rapidly deflating tyre can easily come off the rim at speed if you dont notice it. The runflat sensor picks up tyre pressure BTW there is nothing inside the tyre its just stiffer tyre walls. These tyres can run with 0 PSI so all in all I personally with replace the tyres on mine with runflats when I can/need to.