One of the features of Aperture that I really miss from Photos is the way it handled Raw + Jpeg pairs. If you shoot both, Aperture gave you a great way of managing them. It would allow you to specify which you wanted to import, or it would let you combine them into a RAW + Jpeg pair. It would let you decide, at the time of import, which you wanted as the primary source and you could easily switch between them in the software afterwards. In Photos, while it still combines Raw + Jpeg pairs, there’s no control over the import process, it always sets Jpeg as the primary source and you can only switch between them one at a time in the edit mode.