It works - 10/10 on test-ipv6.com; can't really say fairer than that. I did however enjoy the comedy reverse DNS:

$ curl http://files.dnorth.net/ipquick.php   (05/04 19:19)
2a00:23c4:e81:3100:fdbc:e60a:226e:9903
broadband.bt.com

Oddly enough, broadband.bt.com doesn't resolve forwards to every IPv6 address on their network, so why bother claiming the reverse?