Google offers 'Google Drive Stream' that apes the killer Dropbox features: offline files that smart-sync as needed. Unfortunatly, it's only for GSuite accounts.
But Dropox? Always works great. Always. Never had a problem. So I use them more and more. Too bad I can't encrypt my entire Dropbox like, say, Spideroak but oh well.
You might give gocryptfs [1] a try, with it you can keep [part of] your content encrypted in Dropbox.