Dropbox, OneDrive, Google Drive, Box. They are all the same when it comes to your privacy to be honest. I wouldn't "trust" any of them with very private things. I use them for convenience of stuff I want easy access to/share with family but don't want to just stick up in the public internet for all to see.
Dropbox lied about their access to your documents. Dropbox disabled password authentication for their entire system for a bit, by accident. I'd say that makes them worse than competitors. The whole Ms Rice thing might also make it worse for some people.
We should be using Tarsnap. If only they had a windows client (which I use as a hypervisor, as it has better power and driver support on laptops).