How different is the Sprint 750 or Dash 750 from the C-24 Mk II?

Is it improved enough to justify paying an additional $25,000 to get the new model vs. buying a decent used Mk II?

I like the concept of a fast weekender/pocket cruiser to take down to the Tortugas/Key West once in a while... Not to mention gunkholing in Florida Bay... Maybe a cruise to Bahamas from Ft. Lauderdale if the weather's nice...