I had an older one (W210) for a while and have to say the driving experience is amazing - the words tank and vault come to mind. I also mostly worked on it myself and this older model was very maintainable and well thought generally - the only exceptions were the pusher cables on the sunroof and the insanely-buried evaporator coil. I've also driven the Car2Go Mercedes models and even though they were the cheapest Mercedes, they still drove very well imo. I miss driving Mercedes cars.