I got these to help me pack as much as I could in a single suitcase for Iceland. I was disappointed to realize that the zippers only went about a third of the way around, so it was harder to access the first items added to the bag. I also found that while they did compress, they were still a bit bulky in the middle. In the end really didn't save much room in the suitcase. I ended up using the super large air compress bags with more success.
I'm a huge fan of packing cubes, as I like my suitcase well-organized. I was excited to try these Gonex Compression Cubes, but they did not work for me. The product itself was fine, but partial zipper opening did not work for me.