I agree it isn't a complete set of utilities. Complaints about Garmin's promises aside, frankly if I wanted access to more software, I'd be using Windows, not a Mac. I prefer using the Mac, so I've switched to Mac only on my Garmin for adding my locations prior to my road trips -- I'm happy to create my POI's in Google Earth, convert the KML files, and then transfer them to my Garmin.

Efs, that's not really a good argument.
First off, if you don't want to use Windows software, then there's no way your going to use these maps on your Mac because you need to run Windows, in one fashion or another, to convert the maps to a Mac format. So, you're running Windows.
Then, even if we ignore that point, I suppose you could use the Mac to upload your Windows-converted Maps (however crash-tastic that is, depending on your unit) to your GPS and Google Earth for creating your POI, but what about generating routes and all the other things you just can't do in Google Earth that you can only do in MapSource? I mean, sure, there's say "if I wanted access to more software, I'd be using Windows, not a Mac", but that's not really the point. Being stubborn and limiting yourself as a result just doesn't make sense because The point is, if you want to *really use* your GPS unit, you gotta run Windows. If there was a Mac alternative, I'd be all for it, but there's not. And this software & Google Earth isn't an alternative either. Just a small piece of the big picture.