Testing IPv6 on Windows

I recently decided to test IPv6 on Windows 7.  It has Teredo support, which will use tunnelbroker.net's free service and assign an ipv6 host address to the PC.  I found a few sites with instructions on how to configure teredo including this one.  I was able to get it to work a bit, and tested it with test-ipv6.com. However I wasn't able to get it to work consistently, and I could never get windows to prefer teredo ipv6 connections over ipv4.  I don't know if the inconsistency was an issue with teredo or with the tunnel servers, so I decided to try something else.

While searching for information on ipv6 setup on Windows, I read about the Freenet6 Tunnelbroker.  I downloaded and installed the client software.  I clicked "connect" on the gogoClient utility, and in a couple seconds had a working tunnel:

It also prioritized ipv6 over ipv4, so when I went to sites like lg.he.net, the connection used ipv6.  The last thing I wanted to try was to try ipv6 only.  I couldn't completely disable ipv4, since it is needed for the tunnel.  So what I did was add a static route to the tunnel endpoint:
route add 81.171.72.12/32 192.168.1.1
and then I deleted the ipv4 default route:
route delete 0.0.0.0
I made sure I couldn't reach ipv4 sites by trying to ping 8.8.8.8 (which failed as expected).  Google sites including youtube were ipv6 reachable.  Microsoft sites like bing.com were not (no DNS AAAA records).  Facebook was ipv6 reachable, as was the main yahoo.com site, but not yahoo mail.  Unfortunately many sites I frequent such as hackaday.com and digitimes.com have no ipv6 connectivity, so I won't be going ipv6 only any time soon.