Here at Android Police, we're kind-of-sort-of all about Dropbox when it comes to our cloud storage needs. It's easy to get free space, the desktop and Android clients are both pretty great, and the service itself has generally been bulletproof-reliable. And for us, Dropbox is less about storing things in the cloud, and more about providing easy access to files wherever we go.
Carbonite's Currents works off the accessibility mentality - it's not how much you can store, but what you want to have within arm's reach at a given moment. So, Currents doesn't have storage limits, it has recent-ness limits.