I installed the Sense Home Energy Monitor in October. Since then it has detected (and I named) the dryer, dehumidifier, and a food dehydrator. In addition, it has detected three microwaves (I only have one), one light, five unnamed devices, six unnamed motors, and ten unnamed heats. It says it has detected the furnace, but the furnace is running right now, and Sense says it is not. It also says the AC was running last night and has an average run time of two minutes and 11 seconds.
After three months, what is running right now is "Always On" for 305 watts, "Unnamed device 4" for 44 watts, and "Unknown" for 905 watts. I expected more.
In addition, I got a call from Comcast (security assurance department or something) who tells me that the Sense Monitor is responsible for thousands of DNS queries, amounting to a DoS attack, coming from my router. I can't verify that as being accurate, but I didn't appreciate the phone call regardless. I contacted Sense and am awaiting a response.
Bottom Line: No, I would not recommend this to a friend