I'm currently in the process of moving CMS Report and some other sites I manage to a new VPS. The original reason for the change was to move my sites off of a legacy version of Linux (Fedora Core 2). However, I'm also making the server change because of too much bleeding edge experimentation by yours truly that has brought my server's stability into question. Believe it or not, a reboot of the server doesn't fix everything!
I was also hoping that the transition between servers would be an opportunity to move my control panel from cPanel to Virtualmin. Virtualmin is actually a module for the web-based system administration application, Webmin. More importantly, Virtualmin is used for "managing multiple virtual hosts through a single interface, like Plesk or Cpanel" and the open source GPL version is a free for the using. My hope was to shave off the $10 extra I'm from my monthly fee for the VPS.
The maturity of Virtualmin and Webmin over the past year or two has been impressive and is finally competitive against some of the more popular commercial control panels out there. I've only now started to use Webmin on my office's intranet servers and have found the web-based interface to be a great alternative to using a terminal shell or remote desktop for managing the servers. However, I've never actually used the Virtualmin control panel component live on the Internet. In the end, I had concerns that clients on my server are not quite ready to move away from cPanel to manage their sites. I also had concerns that my lack of experience with Virtualmin would wind me back to where I started, an unstable and possibly insecure server. So in the end, I'm back where I started with using cPanel as my server's primary control panel.
While I decided not to use Virtualmin at this time as an alternative for cPanel or Plesk, it doesn't mean that the application it isn't right for you. If you are so inclined, I would encourage you to give this open source software a chance on your server. If you like what you see but concerned about support, you may want to try the commercial version of the control panel, Virtualmin Pro.