Ok, so doorbell has been in for one week now and overall we are delighted with it. Installation was very quick and simple, excellent instructions and tools included. Perhaps slightly quicker on ours due to the fact that it was fixing to a wooden door frame but all the same it was very easy.
I reused the existing wiring so that it still uses the same ring as well as alerting on the doorbell itself and the app. I have shared the app with my wife and daughter so that we can all see/respond to motion detection and actual ring presses. The camera is good quality - note that we also have a dawn to dusk light nearby so that helps with night vision. The "Live View" feature is also useful if you want to see what is happening at any time.
With regard to wifi, it seems to work better with a wifi point nearby. I moved one of my Airport Express boxes near to the bell to give it a very strong signal. It was too weak when trying to connect to my main router in the middle of the house. Obviously any kind of wifi extender should do the trick and they call that out in their blurb.
So I would thoroughly recommend it. And in use case terms, the fact that you can talk to people to say you are on the way to answer the door (useful for people with mobility impairments etc) is a great feature. We've seen all the delivery folk come and go and tuned the sensitivity so that it doesn't pick up every car that goes by.
We may extend the system by adding a camera that they do, perhaps if January offers come up.
Happy to answer any specifics if I can!