The product works and works well. It makes mirroring my screen to the large flatscreen on the wall simple. I haven't had any issues with having to turn things on and off. As for settings, simply allow your mac to detect displays and it should pick everything up it needs from your screen.
Be aware that if you have a monitor with one of those slightly odd 1920x1050 resolutions (as I previously did), if you are mirroring your display the computer has to output in one resolution that can be displayed on both screens, so you wont quite get a full screen image on a 1080p TV. This is nothing to do with the adapter, but it's worth being aware of, ideally both screens should be the same resolution.
The 1 flaw I have found was that I would get a split second white flash/flicker every few minutes on the Bravia TV connected to the adapter. I almost sent the adapter back believing it to be faulty. A bit of detective work led me to HDMI communication feature of the TV. This is the clever feature that lets connected devices behave like an all-in-one system. For example, if I turn on my PS3, it turns the TV on automatically. Likewise pausing a DVD and turning off the TV will automatically turn off the playstation. The problem comes from the TV trying to communicate with the adapter and confusing it for a split second, leading to the interference I was seeing. Solved simply by turning HDMI communication off when using it as a display.
It looses a star for that small inconvenience.