I previously had a Ring doorbell, then I went to a Vivint doorbell. Both worked great, and I loved my Vivint doorbell. I decided to give the Nest Hello a try: and it blew out my electrical wiring/transformer! Really strange that my wiring could handle the other two doorbells and not the Nest. Buyer BEWARE: you may blow our your transformer, and be forced to call out an electrician to fix it. I did that. My doorbell works again but my chime is still broken. Nest wasn't able to help me with these expenses at all.
My recommendation: wait for Nest to fix their power issues (on version 2). This one takes too much juice, and has a really terrible installation process that could easily cause shortages. Get a Ring or Vivint, and wait for version 2. (even though this one does have some facial recognition which is best-in-class, and is cool)