That combination of 480 mOhm and 17 nC is typical of a 650 V super-junction MOSFET optimised for efficiency in the 100–200 W range, not for the lowest Rds(on) at the expense of switching speed.
The maximum power dissipation of 85 W at case temperature Tc is a junction-limited figure — real-world dissipation depends on the heatsink's thermal resistance and ambient airflow.
