You'll probably not get a consensus, lol!!
I have used the Eagle Creek sil-nylon compression bags for several years but just got back from 5 weeks using these and loved them.
They were developed by a travel blogger, TravelFashionGirl. What I like is that she's sized them so they sit up vertically in the suitcase so they are kind of like drawers in a dresser. Several times i did not even take them out of the suitcase, was able to just unzip them (unfortunately the handle is on the bottom if you have the side up where the zippers meet, but no big deal) and get a clean shirt and unders out without unpacking. Very easy.
Loading them efficiently had a bit of a learning curve since I flat-folded shirts in the Eagle Creek cubes and these are not as wide as those so I did a few trial packs and then was able to leave them packed for a few days to check on the wrinkle state of my shirts.
I wound up using 3 in my RS 21" roller bag. One for shirts, one for cardies & long sleeve shirts and one for underwear, socks, nightgown. I used the 4th one as my back-of-the-airplane-seat cube with my iPad Mini, eye mask, glasses case, ear plugs, motrin, chapstick etc - everything I need during a flight so I don't have to keep getting in to my personal item.
For those that are in to "competitive light packing" they are a bit heavier than the Eagle Creek sil-nylon ones but I loved they way they keep me organized and the weight wasn't onerous to me.
I have no connection to this person or product, just a satisfied customer.
As far as dirty laundry, I sink wash as I travel so don't really wind up with dirty clothes until the last few days.
I also flat fold my pants in the bottom of my suitcase. I stack my extra pair of shoes on the end with the wheels, then just started slotting my 3 packed cubes in. I fit my toiletries bag and my other smaller items in between 2 of the cubes and/or on top of my shoes. Very neat looking suitcase, if I say so myself!