In my and several of my friends' experience, Google Photos search is simply much, much better than Apple Photos. Even though I use Apple Photos personally, I have to admit Google's is just better. My friends always say "if I can't search for my photos easily, what's the point in amassing a large collection?".
It's not just search. Google Photos "slurps" photos at 10-20x the rate of Photos.app with clear indication of what's happening and what's being uploaded.
Photos... just sits there. To get a new photo to my desktop it's faster to open Google Photos on my desktop and download the photo from there than wait for both Photos.apps to finish syncing.
