I am glad to see more competition in this space! I frequently advise non-tech family and friends to choose two cloud providers, and use them to replicate important files.

I stopped being a paid Dropbox customer last year over the Condi Rice issue (otherwise, a great service) but I still use their free tier. I also pay for extra Google Drive storage, which I think is a good deal. The best deal, for my use cases however, is Office 365 home edition: my wife and I each get one terrabyte of cloud storage and up to date versions of all of the Office 365 productivity software (and the web versions are nice running Linux) -- all for $100/year.

I am tempted to sign up for the new Amazon offering, but I already feel I am so well replicated: every photo I take goes automatically to Google+, OndeDrive, and Dropbox; almost all of my working files are inside of OneDrive so get synced; I created compressed archive files for projects and with date stamps save them away in Google Drive; projects stored at bitbucket and github.

It will be interesting to see how well Amazon supports mobile devices and multiple operating systems.

For me one of the biggest wins of cloud storage is being able to choose what is not replicated to my laptops, etc.