I've gotta say, I was impressed with how easy the IPv6 setup was with the latest version of OpenWRT. I just recently upgraded and, with Comcast's native IPv6 support, everything just worked and all of the machines on my LAN grabbed externally-routable addresses. After poking some holes in the default firewall rules, I can connect directly from my machine at work (also IPv6 addressed) to a machine at home without any port mapping or translation. Feels nice.