You can drive like a complete a-hole and it still gets good mileage. The torque is crazy—acceleration from 75mph to XXX is nuts. RWD only, twin turbos, corners like it’s on rails, it’s a blast. Your M5 must border on terrifying.
My M5 is one of the older ones, the E60. It's got a naturally aspirated V10, so it doesn't make the high peak torque or flat torque curve like yours, but when you rev it up(red line is 8500rpm) it gets with the program! You need wide-open spaces to really run it like it was meant to.