Thanks, PIX! I own PhD6, and I like it alot. While I used/use the other products I mentioned, I also used some lesser known (shareware/freeware) products that developed some neat features that were missing in my older versions of those still powerful products (that I mostly did not need to update, esp. for the cost). PhD has given me a lot of precision, and helped me streamline a lot of what I do. My hope was that it could become the ONLY image editing software I use, but my heart of hearts knew that I would still (have to) utilize other products. It's just a bit exhausting at times going from one editor to the next, to cobble together my end-goal.
Anyway: Layers, once you (know how to) use them, are incredibly beneficial for being creative. The current way of going back through the history panel can very easily eliminate some tweaks/edits I've made that I don't want to lose when deciding at what point do I go back if I'm going in the direction I don't want to head through my editing process. I hope that makes sense.
And the thing about layers is, you don't have to use them. You can simply do it the way you are used to, if it gets implemented. It just raises the bar (CyberLink's product) to a different level.
Finally, I don't know how the software was coded, whether adding layers would be prohibitive or not, but I can't imagine it affecting the presets, nor the DirectorZone community (a big feature that many product makers do not have - hats off to Cyberlink for that). Theoretically, layers shouldn't affect anything behind the scenes, with what is currently in place.