I really like FoundationDB. It still feels like that system where if it breaks you will be blamed aggressively for picking a weird thing, so I'd like to see some more success stories, I guess. But if I really care, maybe I should be the success story.

The Go API is also kind of weird, and conflicts with my general thought on Go code that every I/O operation should be cancelable with a context -- they really don't subscribe to that point of view.

Those are the main reasons why I don't use it... but I guess they have the fundamentals down (the "foundation" if you will), so it's probably worth powering through those nits and start using it.