This version of the packing cubes and the clean/dirty cubes are my favorite. The zippers are high quality and the mesh top makes it easy to identify what's in the cube. The solid back gives it some stability and compression versus other cubes I've purchased that have mesh front and back and offer little to compress the clothing. This size is perfect to organize a carry-on. I stack them upright side-by-side and use the top (handle end) of my suitcase for shoes and toiletries. Use them to pack certain types of clothing together or as an easy grab for the beach while on vacation. These are also useful in case the TSA finds a reason to go through your bag, and Officer Cruz doesn't have to rifle through your more *ahem* delicate articles of clothing. That is unless you use those delicates to stuff in your shoes, in which case, the officer will see 'em. (Or so I've heard.)
tldr: these are great, use them for packing and organizing all your clothes