ADuM isolators are incredible. We used essentially the entire lineup on various products at NI... you can push them way past their rated limits... Analog Devices is quite conservative with their minimum guaranteed specifications. Some of their ADuM modules even include an isolated, regulated DCDC, so you don't need an external one. We used that IC to achieve incredible density with a common drain NFET switch matrix design... something like QTY500 solid state DC-switched signals on a 4x3" PCB.I'm using the Analog Devices ADuM1201 for signal isolation for the first time. This isolator apparently handles very high speeds. I may try pushing the serial interface to 1 mbps and see how it goes.