Originally Posted by johnthed0g
Maybe it's me but my dinner suit or tux doen't weigh any more or take up any more room than an ordinary suit or jacket & trousers.
It doesn't, I agree but it also depends on how your packing. If you are trying to just take a backpack and a rollerboard for instance, a suite or tux isn't going to fit. For a women, yes, we can get a really nice outfit in something like that because the material can be lightweight and mallable. A man's suit or tux definitely isn't. My DH does take his tux but he's in construction so dressing up is what he wants to do.
Everyone doesn't want to and that is also their choice.