My daughter and son-in-law have a Ring, and they like it.
Most notably, they had a big problem with porch pirates at Christmas. They and several other neighbors got pictures of the kids who were doing it -- I mean, close-up, quality pictures of their faces -- and far-away pictures of the grandparents who were driving them through the neighborhood in a pick-up truck. They had solid evidence against the people, and the police took the pictures to the local schools. One school said, "Oh, yes -- that's XX and YY -- they're brothers and our students." With the kids' names, the police discovered that the grandparents, indeed, owned a truck that matched the one in the pictures. Slam dunk for the homeowners.
Biggest oddity: My SIL has the app, and it tells him when someone enters /leaves the house. The machine identifies me and my daughter as the same person! We do look alike, but not THAT MUCH alike.
Something you might not think about: He has to turn off the app when they have people over; otherwise, he'd be annoyed with lots of people coming /going.
Even though they like it, I wouldn't bother with one myself.