That is the key difference between runflats and non-runflats, and why I choose to continue to use runflats. They have much sharper turn-in, without the "mushiness" of a flexible sidewall.
I personally don't give a damn about the harsher ride, the instantaneous, darting directional changes are worth it to me. Since my MINI is a street car, I am less likely to need/use the higher limit of grip of softer non-runflat rubber, than I am of the ability to instantly change lanes or dart around an obstacle. On a track car, it would of course be a different story. Everyone has different priorities.