Works great in FL
I have a single collector and an 80 gallon tank. The house and surrounding trees aren't positioned well for solar, so I was hopeful but not overly optimistic. It was first installed in November, as I remember, for about $3K after tax credits and incentives. During the installation and testing, somehow we neglected to turn the power back on, and it ran for a month or so without electricity. After a few days of cloudy weather, showers got a little tepid, so I checked things and turned the power back on, but I doubt it's being used much.
I'd like to make the collector adjustable for the varying elevation of the sun, and provide for "docking" the thing during hurricanes, but that's a ways down my list right now.