Thank you for this and other thoughts. I should clarify that the diving would just be one two-tank dive for me - unfortunately my wife is not a diver. I would say "luxury beach resort" is our primary criteria for the last few days (though I would appreciate good diving)! The dive places you mentioned sound good to me, but the resort quality wouldn't be to to the level we'd want. I chose the St. Regis Langkawi because we've stayed at (and loved) many other St. Regis properties, plus it's an easy hop to Singapore, where we fly home from. A little afternoon rain doesn't bother us, though obviously three days of solid rain really would - it sounds like the former in Langkawi in late August / Early September, but please let me know if I'm wrong.

I think that we will stay at the Borneo Rainforest Lodge, with a stopover in Kota Kinabalu, but would appreciate any ideas of a fabulous beach resort easily accessible from Kota and to Singapore.