No life Diamonds any more unfortunately. That was always generous, but lifetime Silver or Gold (as per AA and QF) would be nice...

I believe there are around 9-10,000 Diamonds, of whom about 70% are based in Hong Kong.

There is a Diamond Plus category which is distinct from Diamond and is by invitation only to the top 1%(IIRC) of Diamond members, and includes loads more perks (like a Diamond card for the spouse). But the 1% is measured by revenue to CX not by miles on OneWorld.

Otherwise, all other Diamonds are equal as far as I know. And even though CX now isn't the CX it was when I first got my Diamond card in 2000, I know I'm going to miss it when I drop to Silver at the end of this month. I had my "last breakfast" in the Haven on Monday, just prior to being op-up'd to First (albeit only to Manila, and I declined in order to be with my family).