Many many years back, I used Sugarsync but ditched them a few months later for Dropbox when they screwed up my file sync.

Recently, I switched from annual to monthly subscription for Dropbox because I wanted to push myself to migrate my files off their service..mainly due to concerns about privacy..

I use Google Drive at work.. it's not great, but it works better than OneDrive. Wanted to use OneDrive as it came with my Office365 subscription..but their Mac and Android clients really need improving.

Almost moved to SpiderOak..but stopped due to their poorly designed Android app.

I can't seem to get myself off Dropbox. I don't use external hard disks for backup now. I digitize everything, so it's important to find a service I can trust...both on privacy and on sync reliability..

The sad truth is Dropbox clients across different platforms and their sync stability is unmatched in this space.