The main reason for me to not switch to Blesta is the missing German language support. I'm not having any problem with the english language personally, and most of our customers are international customers who speak english but in germany we need to provide our website and control panel also in german. If Blesta would have german language support (client area only is sufficient) I would probably already have switched from WHMCS to Blesta. I also know about the Blesta translation project but I do not want to put any ressource into that currently. (Also WHMCS is not offering german language by default but there is a german board that offers a WHMCS translation).