What is it?
There are a few prongs of thinking on this one. The biggest is that an M5 has a broader range of use than an M2 anyway, so there’s a reason for keeping both models in the line up. The standard M5 is for those who just want to potter around in a fast approximation of comfort and the M5 Competition is for those who want a bit more focus and driving keenness. Not many M5 owners are track-day goers, unsurprisingly, given that it’s a 1940kg, five-metre-long saloon car.
BMW reckons that, typically, 50% of a market will drive hard enough to pick the Competition version, though. A bit less in the UK: 30% is the estimate.
Other lines of thinking: I suspect there’s rather more margin on an M5 than an M2, so you can sell ’em both. And it’s not like there’s much of an engine difference between the two, either.