Like Wayne, I enjoy the graphs and also actually seeing the differences that I make to "things".
One area where it was extremely helpful was with my heater usage this winter. Last year I was tracking by hand, noting the on-off times for it. I did some extra work regarding insulating things this year and I can just pull up a graph or chart to see how it worked out. I had unusually frigid temps this year and KNOW that my propane-fired heater stayed off longer than it used to.
Another, more simpler, benefit to me was realizing that every time I hit the bathroom, I was flipping lites on along the way. One bath lite bar used 4 100W bulbs. "It's only on and right off...". Now it has 4 23W CFLs - less than one old bulb and it's also brighter in there.
Little things like are so easy to see the before & after with these devices, it becomes a game to lower any circuit that's being monitored.
And with the rolling blackouts we've had recently here, I have hard proof of when and how long they hit me with them.
So many of these little nickle and dime things are nothing short of ridiculous to me. It doesn't take many nickles & dimes to make a buck and these ECMs definitely help show me where I can.
I can't tell you how many times I've looked at the before & after graphs and said, "Wow..."
I was hesitant because of the price when I wanted to order two ECMs and 20 CTs. I bundled up a few circuits and have the "Unmonitored loads" staring at me. I want another ECM and more CTs.
This thing is worth every penny, IMHO, and I have zero regrets.
And, like Wayne, I think the graphs and charts are cool...