I guess it depends on what arranger you are using... If you've got one covered in sliders and knobs, probably putting anything but your lightest gear on top isn't a good idea. Again, depending on how well padded the lid is.

Some gags have little but a thin sheet of soft foam and the corduroy... Some have high density foam, hard plastic and the corduroy/nylon.

Your mileage may vary radically...

(Loved 124's post, too!)