I was very timid to check out the new Photos.app, and therefore decided to just start a fresh library and have it sync what my phone had through iCloud Photo Library.
After checking it out for a bit, I think I want to move forward entirely with Photos. But at this point, I don't know how I can add in my Aperture library without opening it as a different library (holding down Option), but then don't know how it handles the current iCloud Photo Library.
I checked the menus, and import only preps you for importing photos, not another library. I can open my other libraries, but worried about what that will do with iCloud Photo Library. Do I just need to export everything? Do I open the other library and let it sync?