I back up my photos with Google Photos and Dropbox simultaneously. Dropbox syncs them all at full resolution to my desktop, where I surprisingly still have Google Picasa installed (still so fast and so good!). But truth be told, I rarely open Picasa or view the photos on my desktop these days. If I'm sharing a photo, I still share through Google Photos (when the other user also has a gmail account). And searching through photos on Google Photos is the easiest. But it's nice to know I still have a full res backup on a different platform + local hard drives if I have to drop my Google account tomorrow.