I also wouldn't want to use a cloud storage system that didn't at least have the option to keep a local cache of my data so that I could access it offline and w

I also wouldn't want to use a cloud storage system that didn't at least have the option to keep a local cache of my data so that I could access it offline and with local speed. But that's how most of the "cloud storage" services I'm familiar with work, so it's not really much of a problem.