Ah yes, that cardboard:
I've spent some happy hours up with my bike boxes, cutting off or pulling out several hundred staples. And I'm now in a position to rate them. Your best box, by far, is Marin. It's solid and well built, with staples that slide right out. Schwinn boxes are not bad, but they have a big patch of red on one side, which I suppose might lead to a red lavender? A purple ceanothus? Oh, and I also have boxes for Giant bikes that look as if they spent the journey from Asia being walked on in a greasy engine room. (Full disclosure, I have a Giant, which shows no ill effects).