Flyertalkers can argue this for days without much of a consensus. I fold but I think that is more of a personal preference. I also like packing cubes, but haven't been using them recently. The bag type/shape matters too. For instance I find putting clothes folded in a packing cube or two and the cubes placed on their narrow sides in the center to be a great way to pack a carryall/satchel type bag but that wouldn't work well for a roll aboard bag.