Originally an Indiegogo campaign where an electrical engineer with a background in voice recognition software decided to use similar machine learning algorithms and apply it to electrical signals.
Pro Detecting electronic devices is unique "smart" feature
As more houses come online with Sense installations, the library of electronic devices that the Sense system can recognize should improve. The Sense company intends to add more smart features later such as notifying the user if some devices are faulty once they have enough data to build on.
Con Slow and unreliable about discovering electronic devices
Discovery of devices/appliances is incredibly slow. Booting up your system for the first time you can expect to wait a minimum of 24 hours before the first device is recognized. One YouTube review (video here) has stated that the Sense unit has only identified 16 appliances in over a month for him. Some electrical appliances may never get recognized at all, especially smaller ones.
Consistent identification of devices cannot be expected when connectivity drops or you have to reboot the sense system.
Multiple items for the same appliance can't be merged or grouped.
In short, the identification of electronic devices is still in it's early stages. It is supposed to improve over time but currently it's not a great experience.