Just had a successful deployment of a Nethserver to replace an aging Untangle. I used an old IBM x346 server slapped with a 3Com 3c980c for additional ports (Donald Becker, thank you).
I have a multi-wan setup with 7-8 different groups sharing the Internet. I bonded the remaining ethernet for the Green interface.
Since Nethserver does not have a way to throttle bandwidth per group, I accomplished that by putting them all behind a Cisco switch and do it from there.
Only problem now is how to get some Nethserver swag.