I am very impressed with the features offered by zeroshell. Truly unique, and very exhaustive, and I can see that a lot of efforts were put into the development. Great Work!!!
BTW, May I know whether it supports Multiple-WAN connections, link-aggregation and failover, please? This would help have broadband connections from different service providers used efficiently, and effectively.
At the moment only VPN bonding is supported to aggregate the VPN to increase the bandwidth.
You could read the faq http://www.zeroshell.net/eng/faq/vpn/#vpn.faq3 for more information.
In the future new types of load balancing and fault tolerance will be included for WAN connections.