Great quality! I love that it holds its shape when the cube is not compressed. The cubes are also very sturdy. And they do compress clothing, unlike the ones that I already own.
I don't know if it is just me, but I wasn't able to compress the bigger cube when using thicker clothing. I tried putting in a Summer PJ set, 2 pair of pants, 2 long sleeve tops that are a bit thicker (not sweaters) and I couldn't pull the zipper to compress.
I think the cubes work better if you don't put in more than one set of thicker clothing, which is unfortunate if you travel in fall or winter.
Also, perhaps a second zipper to help you compress will make it easier? I spent some extra time trying to pull the zipper around the cube completely, so perhaps a second zipper to compress would be good.