To the best of my knowledge Flash Earth doesn't allow overlays in the same way. Also you can't tilt or fly about from one site to another etc. In fact all you can do - I think - is browse x/y/z. I know the imagery is better but the functionality is currently zero. Plus it'll probably get shut down at some point as the data is unlicensed. I can't see much point in developing for it.

I've found that our file can give the impression of freezing while it downloads and uncompresses the data set (360+k). But then it should be fine and you should have a menu under Places with the various site types.

More feedback welcome though!