In Eye Candy 7, there is a new option that will allow an effect to be generated on it's own layer when possible.
To find this feature, locate the Eye Candy 7 preferences menu as shown below.
The new options are at the bottom of the preferences window.
Please keep in mind that this does not work with all effects. If it is not an option for the effect, it will revert to the old functionality and duplicate the layer with the effect applied.
Here is an example of what this does.
In Eye Candy 6, when you create a Shadow, it duplicates the layer and adds the effect to it. There is no way to move or otherwise adjust the effect after it is rendered.
In Eye Candy 7 you see that both the original layer and the effect are separated. This provides you with a lot more control and probably some extra time.