**Hot wire** (this tool): best for prismatic / lofted shapes — wings, columns, signs, moulds. Fast, almost no waste, no dust, cuts thick blocks easily. Limited to ruled surfaces (the wire is always straight).
**Hot knife** (like a soldering iron with a blade): best for cutting sheets, freehand work, intricate 2D shapes. Slow, hand-operated, no automation. Hobby-cheap.
**CNC router** (spindle + bit): best for complex 3D shapes that can't be ruled-surface-approximated. Creates a LOT of dust + fluff (eat your respirator). Tooling marks visible. Wastes a lot of foam.
**Manual carving + sandpaper**: still the best for organic shapes once you have the basic block shape from one of the above.
**Hot knife** (like a soldering iron with a blade): best for cutting sheets, freehand work, intricate 2D shapes. Slow, hand-operated, no automation. Hobby-cheap.
**CNC router** (spindle + bit): best for complex 3D shapes that can't be ruled-surface-approximated. Creates a LOT of dust + fluff (eat your respirator). Tooling marks visible. Wastes a lot of foam.
**Manual carving + sandpaper**: still the best for organic shapes once you have the basic block shape from one of the above.