The very fact that we have to ask is what bothers me. Microsoft plainly states that they store the key for full disk encryption, and offer the ability to genera

The very fact that we have to ask is what bothers me. Microsoft plainly states that they store the key for full disk encryption, and offer the ability to generate a new key not stored by them (as covered in the article). They also offer BitLocker in their Pro and Enterprise OSes, for even finer grained, user controlled, offline encryption management. On the other hand, Google claims they don't store your Android disk encryption key, yet for all their other services, they do. (They also backtracked on encrypting MicroSD cards, leaving your actual valuable data exposed yet giving you a false sense of security, but that's a discussion for another day). Chrome syncing (and by extension Chrome OS), for example, is decrypted by your Google account login. You can set up a second, separate passphrase for those services, but again the key is definitely stored by them. Given that they have done some really shady stuff in the recent past (Chromium builds that download closed-source binaries after compiling from source and executing for the first time, etc.), I don't trust them as much as I trust Microsoft. And that's not a lot of trust in the first place.