Are you talking the compression packing cubes, which basically just use a zipper, or the vacuum compression bags which push out air and don't allow it back in?

I've had poor luck with the first, as they really didn't do anything besides maybe some organization. I only tried them a couple of times, but in that case I found rolling was more beneficial as it compacted things more.

I use vacuum bags extensively however - larger ones for most of my clothes, with smaller quart or gallon sized for underwear and socks. In those cases I fold. They compress far better than rolling, which because of the space between tends to give bad compression. You do need to worrya little more about wrinkles if that is going to be an issue. I travel for leisure so can choose clothes that that is not as big an issue with.