If your running a professional business WHMCS is the most secure way to go. Just because it has a price on it doesn't mean it's better, but, well, it is in this case. You'll find WHMCS has the most usability, support and addons available for your usage. It also provides decent analytics.
From what I have heard, boxbilling hasn't been touched in a good amount of time from its developers. If only Aurimas could get a solid dev team lol.
This is the problem with a Free, or nearly Free product. When the original developer loses interest or needs to move on to another product, there are no resources to have someone else continue the development work.
█ Brent Presley - firstname.lastname@example.org
█ Innovative Scaling Technologies Inc. - Enterprise Cloud Hosting and Support
█ 24/7 Dedicated Support, Call us @ 1-888-722-8515
█ www.innoscale.net - Ashburn - Dallas - Seattle - Amsterdam