You can also pay $10 per month for professional monitoring, but that’s it. There are no integrated carbon monoxide or fire alarms, and it’s not capable of syncing up with other smart home devices. This means you can’t control your lights, thermostat, locks, etc. The company says these are coming as the system grows and improves, but for now they’ll be missing if you buy the Ring Security System.
I can see why you’re confused because really any of these three options will do everything you want and more. Is it important to you that your security system and camera use the same app? If so, maybe eliminate abode from the list. You can use the outdoor Nest Camera with abode, but it isn’t a great experience. If you want an outdoor camera that can record continuously and not just based on motion, that would be Nest Cam. If you don’t mind if the camera only records events and as you said, want a system without “big monthly charges,” Ring is probably the best choice for you. They recently launched an indoor camera, you could then add a video doorbell (ideal) or one of their outdoor cameras to your porch. You will need five contact sensors in total. Ring Alarm will include a mobile app for you to review footage and you can expand the system down the road if needed. As it just launched and based on Ring’s history of product support, the chances that it will be outdated soon are very slim.
UPDATE 16FEB2018: After two weeks, I must downgrade my review... it's become obvious that the Ring Floodlight Cam only detects motion during the day. At night, I can walk through the center of my defined motion zone, but the cam won't record until I'm within 10 feet of it. The defined zone is my driveway which is about 40 feet long and we have 3 cars. As long as the ne'er-do-wells only break into the car parked closest to the Ring cam, they will be recorded. A quick Google search for "ring cam won't detect motion at night" will yield many stories of the Ring product line failing to work in darkness. Apparently, the problem has been documented since September 2017 and Ring has failed to fix it. I must say that I'm beyond disappointed. At least I discovered this in enough time to send the cam back to Amazon for a refund.