IPv6 trial on ASUS RT-N66U

[#1]

Seems OK on the face of it, all the tests report OK except the first time I ran http://ipv6-test.com/ it said my browser preferred IPv4 when both available.  Then next time it changed its mind.
My ASUS RT-N66U router doesn't seem to be able to find any clients, even though this is being typed on one. I think I saw someone with a similar problem a couple of days ago so will go hunt.
Edit - Latency is dreadful
Pinging bbc.co.uk [212.58.251.195] with 32 bytes of data:
Reply from 212.58.251.195: bytes=32 time=196ms TTL=117
Reply from 212.58.251.195: bytes=32 time=214ms TTL=117
Reply from 212.58.251.195: bytes=32 time=129ms TTL=117
Reply from 212.58.251.195: bytes=32 time=147ms TTL=117
Ping statistics for 212.58.251.195:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 129ms, Maximum = 214ms, Average = 171ms
BQM

[#2]

Right, more info.
I too was pinging my laptop which is wirelessly connected, see the opening post by AndyH here.
I couldn't adopt his method to get the routers iPv6 address as it won't let me telnet in.  I can't find any reference to telnet in its manual either. I did find a reference to ASUS Device Discovery, so downloaded that and all gives me is the router's 192.168.xxxx.xxx. address :(.
From the command prompt ipconfig /all gave me a number of IPv6 addresses but I couldn't work out which was appropriate.
For the BQM, I've set it up for now with the new IPv4 address and that is working fine. Pings from my laptop continue to be dreadful, pings from the router's Tools page are fine.
Edit - looks like I've found it in the router's GUI - LAN IPv6 address. BQM with that looks to be working.