Run flat tyres will likely result in a firmer ride quality, but it is worth bearing in mind that they will not necessarily offer any greater resistance to punctures. Their stiffer sidewalls may resist pothole damage better than conventional tyres, but a nail will defeat any kind of tyre - a run flat will just allow you to drive further before getting it replaced. They will also cost more per corner than a conventional tyre, so other than the hassle of changing a tyre at the side of the road they won't offer much in terms of convenience.