Well made but still looking for the kind I bought 15 years ago that has firm sides and is about an inch longer. This one is well-made but sides are flimsy. Fortunately I still have one left with firm sides but no one seems to make them anymore.
I started using travel cubes about 20 years ago. In a 26 to 28 suitcase I can fit 2 large-sized, 2 medium-sized, and 1 or 2 small-sized cubes. Slacks and jeans folded in half fit in large-size cube as do shirts folded in half (width-wise), sweatshirts, and cardigans. I use the medium-sized cubes for underwear, socks, nightgowns, and other smaller items. I have a couple of small-sized cubes that are good for non-liquid items that don't fit in my toiletries case like hair brush, rollers, electric toothbrush, and small electronics. Shoes (in shoe bags) toiletries case, jackets, etc. fit around the cubes.

I pack so I can live out of the suitcase, lay them out on surfaces like tables or a desk, or put them in drawers without clothes having to touch the drawers themselves.

On short trips I share a suitcase with my husband. On longer trips we have enough cubes for each of us to use in separate suitcases.