Nest, Ring, and abode all sell cameras. Nest works with Nest Cams including the indoor and outdoor cameras, Nest IQ both indoor and outdoor, as well as Nest Hello. When Nest Secure detects an alarm event, it will trigger your Nest cameras to take a snapshot. If you have email alerts turned on, the cameras will email you a snapshot of the event. It can also send a push notification to your phone.
The Ring Video Doorbell Pro improves on the Ring Video Doorbell 2 and is well worth considering if your porch faces an area that’s likely to have lots of traffic, people walking by, or trees swaying in the wind. The extra $50 could make you a much happier owner, even if you need to bring power to that location. But if the area around your front door is calm and quiet, save the cash and go with the excellent Video Doorbell 2 instead.
Update 3/24/16 - Ring has added “Live View” to their feature set. It allows you to access your Ring Doorbell any time you wish. This solves the problem with #3 as long as you are not on battery power. Obviously, it also lets you “dial in” any time you wish to check out your front or back yard (where ever your doorbell is). This is a feature that I like as every once in a while I just like to see if its raining or foggy at the house.
UPDATE: 1 Year-On. We have had the Ring Pro for One full year now. I've also added two of the chime accessories. I'm just as happy with it now as I was when I wrote this review. We tried to trouble shoot the sound a few times and still have had no luck with it. I think my unit might just be defective in that area. However I still think if this was advertised as a camera only, it would be 100% worth the price and 5 stars. I did have someone point out the sticker over the ring might be the cause of our sound problem, removing it didn't help.
Right now, abode reigns supreme due to the number of integrations they offer, the variety of security sensors, and the fact that it’s an open platform not tied to Google (Nest) or Amazon (Ring). I would give Ring second place due to cost, and it’s bumped iSmart off of my list of recommended self-monitored security systems. My only gripe is that it doesn’t integrate well with its own camera system. Nest takes third, but I would still recommend it. It’s a beautiful system, easy to use, and thoughtfully designed. That said, if Ring raised the bar on their camera integrations, launches an indoor camera, a flood sensor (coming soon), and a glass break sensor, it might just become the system to beat.
Update 1/24/16 - I have found a fantastic use for the Ring Doorbell and Chime. My mother-in-law, now in her 90s, lives by herself. She has become hard-of-hearing and often does not hear the doorbell. By installing the Ring on her door, she now is bothered much less (solicitors tend to recognize it and don't seem to like it) and when someone rings the bell, the Chime, placed by her favorite chair, gives her a better chance of hearing someone at the door.