What kind of deeper integration do you find useful in those competing services?

For me, I found OneDrive being automatically installed on windows and nagging me to sign on too intrusive. Windows setting the default Document folder to onedrive would be convenient if I hadn't already signed up to dropbox, but it's just annoying if I don't have Onedrive. I like the fact that Dropbox isn't part of google or microsoft, which already have a lot of my info in their email services.