Im on a Mac, and see no reason to AB it with my RME. It would be a waist of time. But i have heard recordings with it (both 1212 and 1820), and based on that alone, i wasnt too impressed.
Have you compared the EMU to a like for like RME?
You say the Mac / PC support is irrelevant for gizeh12, but lets just say he wants to go Mac in the near future. At least with an RME he is good to go.
I say if he is getting a good price on the Multiface, grab it.
Another thing for gizeh12 to consider might be to look at some FW options too, like the Echo, RME fireface 400, Motu 828 mk2, Focusrite Saffire / Le.
All of the above will be a bigger improvement over the muddy sounding m audio cards (i came from an Audiophile 2496)