Due to the manufacturing process of the CAD CAM system vs. the vacuum press, only the vacuum pressed devices can be made with a sweet spot. All the Pathology Specific Orthotics that need a sweet spot, or other type of intrinsic accommodation, will be made by the vacuum formed method. The other instrinsic accommodations include: medial/lateral flanges, plantar fascia grooves and EVA arch fill. If you want to include any of these in the orthotic order, the vacuum formed device is your only choice.
In addition, only Vacuum Formed devices can be heat adjusted. The most common adjustment include expansion of sweet spot and raising/lowering of arch height. CD devices can not be heat adjusted, so they are not as flexible when patient fit is an issue.
Keep these points in mind when you consider VF vs. CD on the orthotic prescription.