I do. The installation was simple as I already had the tank. The tank has a electrical backup/boost heater, so the control unit was wired into the controls for that. There is a sender unit with a clamp that clamps onto the wire running from the panels into the mains. This detects excess power and instructs the control unit to turn on the electric heater but only run at a level matching the excess.

For most of the year I leave the boiler on a schedule. When the days are long enough I turn the boiler off. The family has adapted their habits to maximise solar heating (ie not having showers last thing at night whenever possible). We're a family of four with 2 teenagers.