You should read the thread on partner rewards before gloating. You might end up badly burnt.

London to Beijing has a £600 co-payment for taxes and surcharges, and Air China have been known to randomly cancel award tickets when they can actually sell the seats. I believe VS are looking at cancelling the arrangement.

You will never find an award seat in First or Business Class on Singapore Airlines. So whatever you see is just false advertising.

As for ANA, I suspect that one of these days VS Flying Club will massively devalue that particular redemption option. But for now it is still there. There are also issues with connecting beyond Japan but it seems OK if you're only interested in Tokyo...