Vicibox.com's .iso installer uses OpenSuSE. It's also the official installer and installs the latest version of Vicidial (because it downloads a fresh copy during installation!).
Vicibox also installs a clean, unaltered version of Vicidial in which everything ... works! LOL
GoAutoDial, however, installs a slightly modified version of Vicidial that's always outdated (ok: perhaps the day it's published it's up to date, I never checked). But the modified interface always interferes in Vicidial operations. It does also have a few extra wizards and a cuter agent interface, but that agent interface often has freshly installed bugs from the redesign. GoAutoDial's installer is also incapable of Clustering, which can be awkward when you want to grow your system.
Thus my advice is always this: IF you MUST have CentOS (due to corporate software restrictions, or a CentOS addiction of some sort) go with GoAutoDial. It's stable install and it works well.
IF you do NOT have a deep-seated need for CentOS, install with the latest version of the Vicibox.com .iso image. Kumba goes to a great deal of effort to maintain it and there are hundreds (thousands?) of call centers testing this installer and reporting bugs ... and they Get Fixed!