R230, I assume, is the generation in question.
The Mercedes-Benz with its innovative but costly to repair and maintain ABC suspension, hydraulic roof, etc., is just as likely, if not more so, than the Porsche to rack up thousands of pounds in repairs and maintenance costs.
Of course, you might not be experiencing any issues at all; after all, you could be relying solely on the stories you read about in online forums. Plus, the m113 engine is both innovative and somewhat resistant to damage.