Engine lives
Regardless of the hours accrued, isn't there a calendar life (12 years springs to mind) listed somewhere in CAP747 ? As for the better engine, thats horses for courses. Lycomings eat cams and lifters but spares and product support are easier to get, not that Contis are that hard to get bits for and dont have weaknesses (starter adaptors and crankshaft counterweights spring to mind).