I thought I'd just post this page from the Rust Locoblade as an example of what I love about cardstock models. I have a smallish collection of unmade cardstock models I've picked up over the years, a collection that will remain unmade. The reason that they'll stay 2-D is not just that I'm short of time to build them, but instead that I love the graphic appearance of flattened out parts with all their tabs and numbering. I think they are works of art in themselves, sometimes worthy of framing and hanging on the wall.
My model parts are laid out with some lazy abandon, too much space between them, particularly considering we should all be saving paper for the sake of the planet. The act of laying out parts in as efficient a paper saving way as possible is actually the most time consuming and difficult part of the development process. Like a really tough puzzle with pieces that may fit together in the final 3D model, but don't add up on a sheet of A4. Hence my liberal use of white space. Have a look at www.fiddlersgreen.com for some examples from the masters of tight pattern arrangement.