Altium Designer 14.3 brings a beneficial enhancement to the use of Polar Grids for component placement in the PCB Editor, in the form of automatic placement rotation. As you move a component over a defined grid of this type, it will automatically rotate to the origin of the grid, as you move it around the grid. Use this feature, in combination with standard object rotation – Spacebar (anti-clockwise), Shift+Spacebar (clockwise) – to align your components exactly as you need them.

An example of Polar Grid automatic rotation in action.