first, it's better than the other monowall/firewalls because it has vmxnet, mui-control and heartbeat monitoring.
second, i wrote a document that i thought would be made available with the appliance in which i wrote in more depth how it works, and how it's setup.
if it doesn't work out of the box, be sure your host has the NICs connected correctly and the appliance LAN ip address is in range of your workstation at which you are trying to connect. it sometimes helps to connect only the first NIC of the appliance (which would connect to the LAN adapter)