My logic was basically the same as yours, figuring the data sets might be a gold mine of data withheld from the unwashed masses. Alas, the data set images are just a selection from the publicly-released raw images. There seems to be other stuff there having to do with records of rover operations that you can replay, but nothing compelling enough to put up with Maestro's big drawback: It's written in Java and it's dog-slow. Seems to take several minutes to render a single display, and when you try to animate (perform simulated rover movements and stuff like that) you can feel your hair turning grey. Of course, my computer's getting a bit old, just a 400 MHz machine. I estimate that Maestro might perform fairly satisfactorily if you have one of the latest 2GHz+ machines with a gig or so of RAM.