Here's more hands on experience with the Xbox 360 Video Store, 24 hours after its launch.
Speeds Should Get Better...Maybe: The system is getting hammered, and downloads are going slug-slow, or failing all together. The service stopped my movie download half way, and wouldn't download more unless I bought it again. Then I tried buying an HD movie, which failed, but took my cash anyhow (see image)
If the system knows it took my money without showing me what it had to show me, don't you think you should give me a refund?
Other things I've learned:
•You can't FF or Skip Chapters in a movie until its completely downloaded.
•Also, downloaded movies can't be re-downloaded, even within your rental period.
•You can't download movies on other machines if you're within your grace period, either.
•There are no movie menus, ala DVD.
Xbox 360 Video Store FAQ [Gizmodo]