@collage1, I did a test yesterday in my carryon when I returned home. The last time I took a carryon was when I went to Italy 5 years ago and rolled my clothes for the first time.(No cubes).
I started purchasing cubes with my regular sized suitcases. I take these on trips because I just want more space and not have to use a quart bag. I generally have more space than I need and I have loved the cubes for the organization. Plus, clothes will tend to wrinkle and shift when the luggage is held upright after packing.
So, on this trip I used 2 large cubes and they fit. I had a few other things but ended having to put quite a bit in my small backpack. Curling iron, makeup bag, quart bag, shirt.
When I got home I wanted to see if I could get all that stuff in by rolling and not using cubes…and it all fit with no cubes.
So, for me to fly with my carryon and get everything in there, I can’t use regular cubes.
I would like to buy a compression cube and try it out, though.