My separate handheld GPS (a Garmin) gives me locations such as "N39 24.383 W76 49.327". To save these with my photos in Photo Mechanic, I copy this from the Garmin file, and then have to tease it apart into six pieces to use the "Set GPS Coordinates" screen. I wish I could just enter the single value, and that Photo Mechanic would parse it for me.
And for those times when I'm befuddled by all this copying and pasting (it happens) and enter coordinates for the wrong picture, I wish there was a way to delete them, not just zero them out (as others have said above). [I see people mention ExifTool, but I haven't tried it yet. Perhaps that will do it?]