Francis,
I have used for many years Geosetter to enter GPS coordinates in pictures. This is a very nice program, able to embed coordinates in any Raw file in many different ways, thanks to ExitTools.
The only drawback is that it is much slower than PM, and add an extra step.
For NEF, Jpeg files, PM is incredibly fast. For RW2, it is as fast but add the extra xmp. This is certainly going to disapear when people at Camerabits will have time to solve the problem (certainly after the Catalogue is released).
Fredetic