I am using Screened Bottom Boards in Brisbane, mainly as a Small Hive Beetle trap.
Pro - easy to empty/refill trap from the rear of the hive without disturbing or opening it, or even going near the entrance.
Pro - Uses cooking oil: non toxic, cheap, easy to get. (Not sure how DE or lime would go with the humidity???)
Con - Oil gets alot of SHB, pollen and rubbish from the hive floor in it and can get pretty funky within a few weeks.
Con - If the tray gets a hole in it all the oil will leak out, and the remaining goo (oil/pollen/dead SHB etc) will ferment really quickly. (I think this caused 1 of my hives to abscond).
I currently use Stainless Steel mesh and thin aluminium roasting pans, but they have tended to get pin holes and spring leaks after a while so I am looking into some better trays, maybe even making them from aluminium sheet.