I've had several of the Sea to Summit packing cubes for several years now and they are the BEST organizers, hands down. I travel frequently by air & auto. The last thing you need when meeting airline baggage requirements are organizers constructed of unnecessarily heavy fabric, or that feature buckles which add no function and only increase weight and bulk.
Sea to Summit organizers are virtually weightless. Not only do they simplify packing, but they protect my delicate clothes; organize my suitcase as well as hotel room, and help keep my belongings unrumpled during TSA searches. I've had my organizers for ~7 years now, and they still look new. I won't leave home without them!