Let me add one thing, its not that any other manufacturer has less reliable cars, every car, whether german, american, korean, chinese or japanese is a reliable car: means it will not leave u stranded in the middle of the road.
Merc are reliable cars but they have more expendables/consumables. You'll have to frequent workshop more then the other rivals. There are more thing to enjoy in a Merc/BMW but there are much more things to go worse and that too quite quickly, eventually it becomes a drain on your pocket.
& btw, my last 2 Merces (E320 & S320) were better at Bar-B-Q, means they both self-destruct' themselves... thats another point to ponder 