Having bought Aperture 3 for £43 through the Mac App store, hopefully this will be a simple question - Does Aperture 3 do or have the concept of layers? I can't seem to find a definitive answer to that - so far, I've worked out that it doesn't/can't.
Agreed, all changes are reversable and do not impact the original just a version that you may export at some time but the point I was trying to make is you do all your changes to one layer.