There is a known issue with Google Drive specifically: it doesn’t necessarily upload changed files in chronological order. Combined with Scrivener’s frequent automatic saves, this can result in the project’s master index file being out of sync with the actual contents of the project, ultimately leading to lost work. We advise against Google Drive for that reason.
Regarding other services, any service that works like Dropbox does should be fine in theory. In practice, extra backups are never a bad idea. Best practices for using Scrivener with cloud services can be found here:
https://scrivener.tenderapp.com/help/kb/cloud-syncing/using-scrivener-with-cloud-sync-services
Recently, I’ve seen an unusual number of support tickets that seem to be related to misguided “smart sync” operations. A “smart” sync is one that downloads files to the local system only when needed. Depending on your usage and the speed of your internet connection, though, this can result in the content of a file not being available when Scrivener needs it. Most people find the resulting “blank” documents extremely disturbing.
I also especially recommend against iCloud’s “Optimize Mac Storage” feature. There have been a few cases where this feature “optimized” projects off to the cloud while Scrivener was actively using them, leading to save errors.