There are some very good aspects of the automatic organising of your images because Google Photos goes way beyond just checking embedded geocoding or even metadata. The technology genuinely uses an artificially intelligence approach to image recognition and can identify things and places. However it is not awesome (yet!). It gets a lot of the photo content right, but for my photos there are more misclassification than I would like (see notes below) Also I have not seen the people (face recognition) come up despite the fact that I have been using facial recognition in Picasa for several years and many of those photos are in my on-line google photos.
There are a few obvious misclassifications in the grouping that goggle plus photos finds on your behalf. In particular for me it has taken images of the moon I taken of the full moon, and these had been placed in three groups. Firstly of two place I have not been to (and I have been to a serious lot of places) Segovia and Malaga. The interesting thing about the Segovia grouping is when I clink on that grouping it reports no results! The Malaga group did show the full moon image (taken in my backyard BTW.) The third place grouping was Paris, which I assumed Paris France, a place I have been too but have no digital photographs of, especially on-line. The two images selected are definitely not Paris, France. So I tried investigating how to remove these photos from the grouping. The Google Photo Help only gave me a message it can't be done on a computer yet! So I will have to wait, but not being able to help improve the classification
My last issue, and one that I haven’t seen this discussed elsewhere is how to find those things that are not being automatically found by google photo. If you take a lot of photo and they are being uploaded indiscriminately but the vacuum like google photos backup & sync utility, you photos could quickly become a mess, and it will difficult to find very special photos except by remembering the date a photo was taken. Again it would be very nice to be able to “seed” a new grouping by creating an album of the characteristic photos and then let google photo find other similar photos.