The priority baggage handling is nice - it does work pretty well, certainly at ports within Asia; normally at ports elsewhere. But they are quite relaxed about cabin baggage also for Diamond members at least, so I very rarely have check-in bags when travelling within the region. I've only ever used the excess checked baggage once, but it saved me quite a lot of money on that occasion.

The other benefit for Diamonds is that you get guaranteed availability on any published economy fare (& full fare J) at 24 hours notice. For leisure trips in the region this can be worth a lot. Golds get guaranteed availability in any economy fare at 72 hours notice.

Award bookings also seem to be much easier to get for Diamonds than for others - I never seem to have much difficulty, for example, getting business upgrade awards to London with a couple of weeks notice, which others have claimed is near impossible.

But note that you have to go through all the tiers on CX - to get to Diamond from scratch requires 210,000 club miles. (30K to silver, reset then 60K to gold, reset then 120K to Diamond). I got there in 14 months - it's best to do it when you first come to the region since that is when you are most likely to be doing your "familiarisation" tour! Being AA Plat you get the priority check-in, lounge access and so on while you're working your way up the CX ladder (although if you are in J anyway this is less of an issue).