I would not say the 2-prong power cord of the Cambridge is a negative thing. The power connection is still a standard IEC inlet, so you can use any power cord upgrade. Some electronics have a floating internal ground plane and do not use external ground, so that is why you will only have 2 prongs. It's not really a bad thing.
That being said, with the Oppo, you can do the following mods/upgrades:
Or there's always Modwright tube upgrade if you want to do that expense.