Apple started distributing updates through their own Content Delivery Network instead of using the big boy networks that they've used for years. This explains the long waits for getting the updates.
It took me three attempts before the update started to download, and the download took nearly an hour. Not a positive experience.
I'm sure Apple was field-testing their delivery network and will make significant improvements for the future.
So far my experience with Apple TV 7.0 has not been positive, at least one one case. A radio station that worked flawlessly prior to the update now keeps dropping the connection. I figured these were direct streams from the content providers, but if Apple is channeling all radio stations through their own servers now, that would explain the problems.
No iTunes Radio here in Canada yet. Boo!