USM double doubles your sharpness control: You can set up a radio, an amount and a threshold for Dark Halos and different for Halcones de Luz. As proven expert color correction Dan Margulis, light halos tend to be more visually offensive and need to be attenuated, both in intensity (quantity) and thickness (Radio).
A predetermined Prepress tough USM is 500-1 (within amount), which can always reduce the opacity of the layer. Double USM gives a more natural effect with (400-1.5) for dark Halos and (250 to 0.7) to Hawks light, about half of the intensity and half the thickness.
Also it is known as High-Radius, Low Amount: used to shape and a 3D appearance. One starting point would be (50-50) for Dark Halos and (30-30) for Light halos. As you can see, the radios are unusually high, while the amounts are below the values you would expect.
With Double USM nothing prevents you from experience: a creative sharpening may involve a standard USM to Dark Halos (say, 400-1.5) and HiRaLoAm for Halos Light (say, 30-50) to get the best of both worlds.
Create and apply your own presets sharpness! Note that, with respect to sharpness, there are no perfect receipts or absolute values: always depends on the resolution of the image, the subject and finally your own taste.