Yeah, we run our whole operation on Virtualmin/Cloudmin/Webmin. There’s often some “it’s not what I’m used to” pushback from users, but usually once they get in the swing of things they like Virtualmin okay. I think most of the Virtualmin-related helpdesk tickets (and there are not THAT many of them) revolve around finding things - the Webmin/Virtualmin distinction is a little difficult for people, and the menu organization is perhaps a little confusing.
We also run our operation on Webmin/Virtualmin with WHMCS. One of the reasons we chose it is the ability to use FreeBSD as our Operating System of choice plus we like that it doesn’t take complete control of our systems.
We also receive the odd HelpDesk ticket regarding how to do things. We’ve been creating knowledge base articles to resolve most of these.