Ring, maker of one of the original (and still likely the best) connected video doorbell, has launched a comprehensive home security system called Protect, which retails for $199 and includes a base station, keypad (for arming and disarming) a contact sensor for a window or door, a passive infrared sensor for detecting motion and a Z-Wave extender for adding range to smart home devices that use the standard.
When Ring worked as advertised, it delivered on all its promises. I never had any suspicious characters press the button, but I blew my neighbor’s mind when I communicated with her—quite easily, through the doorbell—while I was on vacation in wine country, 80 miles away. Unfortunately, I couldn’t help her get into her house (she had locked herself out), but it was a striking illustration of what Ring can do.
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.