How much gadgets & accessories are you packing to travel with ?? We owned & used a variety of eBags and Eagle Creek packing cubes - eBag's small & medium cubes are big. I used to take more items on the road & they all fit into the slim packing cube (large/full size) - http://www.ebags.com/product/ebags/s...uctid=10153227 - that's the biggest that I've ever used for extended trip & family cruise vacation.
Otherwise, Eagle Creek's slim half cube is what I typically take along, and it's easily to slim into my Timbuk2 messenger bag and/or slim backpack, in addition to 22" MLC, etc. EC's Pack-It Sacs in S-M-L sizes might be worth checking out, it lies flat although I use one mainly for storing all the loose items - keeping it together going thru security/checkpoints, etc.