I write on a laptop, and use Microsoft Word. When I was working, I would use the laptop before I went to work, then I would write longhand on my breaks. When I got home at night, I transcribed what I'd handwritten into the computer, and then continue on into the computer. I couldn't write longhand for an entire book, I don't think. Too often I decide to add a paragraph in between two existing ones, or some other addition that pushes text down, or brings it back up, or alters it in some other fashion. Also, I often get halfway through a sentence, then think of a better, more proper way to begin it. So all I have to do is hit BACKSPACE and write whatever it is I intend.
I'm thankful for computers/laptops/word processors because they've made the physical part of the process so much easier. But I think they also kind of spoon-fed us in some way. I remember Stephen King telling the story of when he was writing the first draft of Dreamcatcher. This was right after his accident and it hurt too much to sit at his desk. So he wrote the first draft of that book with a pen in a huge journal. All 800+pages of it. He said it changed the way he thought of the language for the very reason I just mentioned: he had to really think about what he was going to say before writing it down, because it wasn't just as simple as pushing a button a couple of times, or running things through a machine.
With that said: I continue to be spoiled with computers and if I spot something I don't like, I can highlight, delete, re-format, re-tool, re-whatever, and it makes the process a little easier---which is great, because it's enough of a headache already. I have nothing but the utmost respect for writers of the past who worked with pen/pencil and paper and typewriters. Because their progress was not a bunch of ones and zeros on a page, it challenged the way they looked at their prose. I'm hoping to get my hands on a typewriter just so I can feel what it's like to utilize the language in some sort of degree like they did in the past.