content search (all mailboxes)

Has anyone had any experience running a content search over all mailboxes in your tenancy especially in a larger environment without several thousand users/mailboxes? 

This article:

https://docs.microsoft.com/en-us/microsoft-365/compliance/content-search?view=o365-worldwide

Suggests if you ran your search over 10,000 mailboxes, it would run and provide the results in 10 minutes. Which sounds to good to be true based on the equivalent searches of on-prem Exchange Server releases. Is this your experience, that the searches are super quick to complete and return results?