Before we get all up in arms about a letter being in front of a model, let's look at the M550d xDrive.
1. 4.7 seconds 0-60
2. Close to 40 MPG estimates. That's in prius territory in terms of fuel economy, and I'll let you decide the class of fun it's in.
3. AWD + Torquey diesel will probably give some absurd launches
4. AWD + some blizzaks will give you some serious snow-crunching ability
5. There's a wagon version that goes 0-60 in under 5 seconds, and also gets close to 40 MPG estimates.
I bet if BMW didn't throw an M in front of these models, everyone would be raving BMW.