I haven’t driven one but my assumption is that it drives like a Cooper S with a bit more urgency and top end. I.e. minus the unforgiving nature of a JCW. I’m not on runflats, but I am on 18s, and I assume my (passive) stock suspension is harder than a Cooper S. Whenever I drive my mum’s Cooper S I always think it’s much easier to live with but just lacks a little power at the top end compared to my JCW.