Neil Gaiman pointed out when he was editing the Sandman: Book of Dreams short story collection that some stories that should have been 3,000 word were coming at 6,000. It was part of what sent him back to writing by hand. Computers, I think, sometimes make the words come too easily.
When I write by hand, I write faster and more steadily than I do on the computer (in theory; I write pretty steadily on both these days) but ultimately, i produce less content and it takes longer.
The downside of writing for deadlines is, I haven't always the luxury of doing it on paper. Not if someone's expecting something Right Damn Now.
My handwriting improves the more I handwrite. I think my hand just settles into doing it again. Plus, I have to be able to read what I write well enough that it doesnt' trip me up when I go to type it.
That said, I don't keep perfect and beautiful notebooks. I'll write a chunk of a scene, then scribble out a line and write something else.
Something else fun to do: Get a journal that isn't lined. Write a story from one end, and then flip the journal over and start writing another story from the back. Or do two different colored inks. It's amusing.