Had it for a couple of weeks...

It's better than Maps.Google for two reasons: better resolution in the photos taken from orbit; it's not browser-dependent (maps.google doesn't work in Firefox), though it requires a live Internet connection to retrieve the images.

I discovered something strange about it while "flying above" the Himalayas, and neighboring regions: the code that wraps the flat images onto a globe causes distortion. I suspect it's only noticeable in regions with a high range of verticality... I haven't tried it over Manhattan yet.

The coolest thing I've looked for and found, so far, are the Pyramids.