Aperture to Photo Transition - Adjustments
I have just been looking at the presentation video "Advance in Core Images" from WDC: https://developer.apple.com/videos/wwdc/2014/
What I have just realised, is that although images, folder structure and metadata can be migrated from Aperture to Photo - Images adjustments very likely cannot be migrated - Apple are changing the underlying mechanism by which image adjustments are being made and the stage in image processing where they are being made. For example, even if both tools have a "Brightness" adjustment, the effect of a 14% change in brightness may well be different.
Also, the set of editing adjustments in Photo will different than Aperture - even if you could migrate some adjustments - what would be the value of migrating some adjustments, but not all?
In an Aperture to Lightroom migration metadata and folder structure information can be retained, original and final images can be retained, but the sticking point for may is that the adjustments and the reversibility of those adjustments cannot be retained. You cannot say, I want the same image, but with a little less sharpening and no noise reduction.
It will be no different in the Aperture to Photo migration.