Pros and Cons of hosting on Amazon S3

I signed up for an S3 trial account and uploaded a Storyline project to test out. It seems to work very well. Their cost calculator is also nice, so that one can gauge probable monthly costs for hosting. They also have a few different means available to secure your content.

I was wondering if anyone is using Amazon S3 for medium to large-scale (>5TB/month) project hosting. Has anyone had any problems with hosting Storyline projects on Amazon? Anything else to be aware of with this type of hosting?

This is my list so far:

Pros: ease of use; very inexpensive; multiple means of securing content; backup of content; high availability(?)

Thanks for your input!