Packing cubes have real drawbacks. The main four:
- Added weight. A full set weighs 4 to 14 ounces empty, which counts against strict airline weight limits.
- Wasted space. Rectangular cubes do not always fit the curved interior of a suitcase. Small gaps between cubes become dead space.
- Wrinkle risk. Compression cubes over-squeezed can press permanent creases into silk, linen, and structured fabrics.
- Slower access. If the cube you need is at the bottom of the bag, you dig through the stack.
For most travelers the tradeoffs are worth it. For carry-on-only flights with strict weight limits, or for people who mostly wear structured clothing, lightweight soft cubes beat compression.