Doubles space required to store photos/ requires TONS of time - Easy to search though - If you back your phone up to your desktop or laptop, and have your phone synced with google, those photos/videos upload MULTIPLE times into Google photos. There's no "Duplicate" finder or similar. It's easy to tag people in photos, but there is NO way to tag a face it claims it doesn't see (so it won't tag the person, but if you search by name, said face shows in results, untagged)