Not 100% related, but 6300M with SmartRate will not do 10 (as expected), but will do 100/1/2.5/5.
Any idea if R0X41A will do 100? The datasheet seems to imply that it wont.
Oh, and one note. If you use Intel AMT/vPro (out of band management for desktops and workstations), it may no longer work with a smartrate card/switch, because it limits the NIC to 10mbit/s when the computer is sleeping or turned off.