From the freedom/privacy standpoint, however, I'm not sure. I find it surprisingly easy to imagine a US government agency empowered by anti-terror laws to get access to my data.
This is why I want encrypted cloud computing for all my stuff. I dunno if the large players could actually do that and have the US govt be ok with it.
But then there's also the fact that i have access to a decent set of hdd's and can store it locally rather with ease.with the cost being the attention and time of running smartctl once in a while to check the health of the hdd's and getting a backup...
Verifying that data going across the wire is encrypted is fairly easy to do.
You check the data going out is encrypted and that it is encrypted when it comes back. Is that enough verification for you?
Depending on how much you trust the vendor you can go further - run it in a debugger and check where it gets the key for example.
You lock down access to files like private keys as much as possible to minimize the possibility of this.
For example (not affiliated): https://yubico.com/