I installed Sense on 11/16/2016. I was shocked (haha) at the amount of continuous electricity use and frequent spikes in use. Within a couple of days, it identified an "unknown heating device", which turned out to be a small electric water heater that we installed when the home was built, supplemental to our natural gas tankless water heater, to circulate hot water to a distant bathroom.
Watching a few more days revealed a consistent 20+ KWH/day of electricity use by this one item. That equates to about $72/mo for this thing to run, or 1/3 of our winter electricity bill. And I can only assume much higher use in the summer, as the plumbing runs right alongside the A/C supply ductwork, enclosed in the finished basement ceiling.
I will be switching to an alternative method of circulating the hot water (on demand call for hot water with Z-Wave occupancy sensor and a recirculating pump, appx $500 investment). This is similar to the original investment, but without the ongoing operating cost (I believe this will drop the energy need by 95%, plus the gas heat costs significantly less than electric).
The monitor has also identified our microwave oven, sewer grinder pump and our downstairs fridge. It also identified an unknown device which has turned out to be one of the HVAC fans.
I'm anxiously awaiting for it to discover/discern other devices. I'm surprised it has not yet identified our electric dryer, washing machine, curling irons, garage door openers, the 2nd fridge and freezer, and any lights as of yet. I'd like to see this discovery occur more quickly.
A 2nd big surprise is to see just how little most of the high wattage devices consume over time. I'll know more as others are discovered and tracked separately over a longer period of time. But the microwave and grinder pump, while requiring larger circuits to run, are only on for relatively short periods of time and therefore don't accumulate as much usage as smaller items that run for longer durations. (Makes total sense but the display from the Sense Monitor makes this very clear).
A 3rd big surprise is the amount of "always on" usage. This is currently 1,099w. Computers (several), routers/switches, chargers, radon exhaust fan...seems high so I hope to identify a simple change to reduce that as well.
So in summary, this thing has already revealed enough electricity usage that I can eliminate that It will have paid for itself. Maybe our situation is an exception. It's slow to identify new devices (would have rated 5 stars if it had identified significantly more devices to date) but it has given me a much deeper awareness of the sources of my energy use. And that's what I was looking for.
Bottom Line: Yes, I would recommend this to a friend