I had Mike look at this site, as I don't know a thing about this stuff.
Don't know about Terrafly, haven't use it.
About Terraserver.microsoft.com : the site has changed from the last ime he used it. But, the pictures (at least of our place) are the same. Same close up, same details.
The big difference is, he was able to save that whole picture from a specific menu. Now, you can save it only chunk by chunk, and have to reassemble everything yourself. Very slow process.