You're only half right, gardencat. The truth is that they won't notice either one.
My philosophy is that they only way anybody will know if your clothes are wrinkled is if somebody takes a picture and the wrinkles show up. If that happens, just have the photo digitally touched up. This may also work for faces at your option.
I think bringing irons is silly, but then I think bringing half the things I see people hauling aboard ships is silly (duct tape?)
Did you hear about they guy rushing to catch a ship at FLL who made a last minute stop at a drug store to pick up a few things he forgot. He arrived at the counter with condoms and Bonine. The clerk looked up at him and said, "Hey, if it makes you sick, why do it?"