+1 for this. VestaCP is relatively new to the game, and I have had rock solid support with cpanel,I've heard good things about VestaCP. WebMin is very basic.
Honestly I'd invest in cPanel/WHM if you're on a VPS or dedicated server, it's hands down the best there is and the support you can get from them if needed is top notch.
Forgot to mention InterWorx actually we do prefer InterWorx over cPanel , better secured , better functionallity that cPanel.
You should tell us what you need cPanel for? if is only for you then really go for Webuzo single user VPS control panel you will love it.
Plesk is pain in the ***
We don't like Plesk for lot of reasons. I'm telling you to go with Webuzo , based on our experience with over 400 active installations currently , we never had any issue regarding the stability and security.
From the free options Webuzo is top software. I'm not saying that Plesk is not good for daily usage but you are asking for FREE software or I'm wrong?