To me Naomijoy12, packing cubes are simply another piece of excess weight that I don't need. I use ONE packing cube as my toiletries/first aid bag and that's it. I do use some Ziplock bags which you could call a 'packing cube' I suppose. What's more, a ziplock bag can have the air compressed out which a packing cube cannot. So ziplocks are in fact not only lighter but compress better than packing cubes.