This is how the Sony manual describes this function: "Sets whether or not to display the Phase Detection AF ranging points on the screen" So for a moment I thought that this just displays the points, and doesn't necessarily affect whether the camera uses them. Then I found this quote: "If the Phase Detection AF ranging points are displayed inside the selected auto focus area, the camera focuses using the Phase Detection AF and the contrast AF in combination." So I guess displaying the points also means using them (assuming the other conditions are met, i.e. compatible lens, f6.3 or less, etc.). That said, do people use Phase Detection on a regular basis? Any drawbacks to use?