We got some packing cubes for a trip later this year where we will be restricted on luggage weight, but we practiced with them on our last stay at Disney. I love them. Can't believe how much stuff I was able to get in them. We usually only stay 4 or 5 nights, but before the packing cubes, I was using a bigger suitcase. Was able to use a smaller suitcase with the packing cubes with the same amount of clothing, or maybe even more. I didn't even unpack my cubes, just put them in the drawer as is, and then just removed what I needed each day. We don't swim, so I had no wet clothing to deal with. DH did not keep his clothing in his cubes, and thought when it was time to go home he would just jam all his dirty clothes in the suitcase, Well, he had a hard time getting the clothing back into the smaller suitcase.
I usually travel with the vaccuum bags, that i would just sit on to remove the air, but I definately think the packing cubes worked better.
If in doubt, go to YouTube and find videos on using packing cubes.