Alejandro Teran wrote: no, my isp still has not gone completely ipv6 native, but at least does have a POP for SixXS there. My IPv4 and IPv6 ping average about the same because of this (about 50ms). You either don't have a POP that is near by, or on mine when I initially setup with 6to4 any-cast to try IPv6, it had to jump an ocean or two to get to the nearest setup transfer station, and so I had an unusable average ping of about 400ms. In short, you either need to find a closer POP, are mis-configured, or out of luck currently, check back later...

You should do a IPv4 traceroute to the PoP, as that covers the path the tunneled packets take and will show where the latency is caused. Note though that there are a variety of reasons why there is latency, one of which could be queing of packets by devices or at the ISP. See also the "slow" FAQ for a list of other possibilities.