I got my first M5 in '87, an inline 6, great balance, best engine BMW ever had, kept it 13 years. Next in 2001 was a V8, not nearly as good a handling car, but much more luxury features. Its M power button was special, I really regret trading that one in on my first X5. I thought the V10 M5 just wasn't nearly as good at handling, too front heavy, so I went large. The X5 M is awesome if you like the size. I like sitting up, great visability, not going to motocross in it.