I made a cake on Fri. for a party yesterday...made bc and used merigue powder for the first time. I noticed that my bc was easier to smooth, much easier. And for me, in south Alabama near the beach, it did help to keep it from softening and beginning to melt quickly. Here I have to keep an iced cake in the fridge until the last minute or it will begin melting very very fast - it gets super soft and really shiny. In a totally ac'd, very cold, and very well sealed house, I'm sure bc w/out meringue powder would probably hold up fine. But my MIL's house (where the cake was yesterday) is right on the water and it's an older house, so it's always just a tiny bit humid even inside. We even have to put rice in our salt shakers here to keep it from clumping up from the humidity - if it clumps it won't come out of the shaker!! lol Very frustrating! lol
I'd be curious what kind of icing big bakeries use....like grocery stores and wal-mart, etc. It tastes like doo, but I've never seen one start melting, even in the heat down here outdoors!! lol If someone knows, maybe we could take the base recipe and tweak it a little to get the stuff more palatable/tasty??!! lol

Jennifer