There’s some discussion going on in SF blog circles about what it means to write quickly or to write slowly, and whether books that are written quickly can be written well, and so on.
This is actually pretty simple. For someone who wants to be a professional writer (i.e., wants to make a living at this crazy business):
a) It’s better to be fast than slow;
b) It’s better to be good than fast.
As to whether a book that is written quickly can be written well, I find this a deeply uninteresting question. There’s absolutely no way to tell from the text whether a good book was written in three months or three years; likewise there’s no way to tell whether a book that sucks raw eggs was banged out in six weeks or slaved over for a decade. From the reader point of view process simply doesn’t matter; product does.
I mean, look: George R.R. Martin took five years to write A Feast For Crows; I took three months to write Old Man’s War. Both books got nominated for the Hugo, and both books got beat by Spin, which I rather strongly suspect was written by Bob Wilson in a space of time that was longer than three months but shorter than five years. To the extent that the Hugos are an arbiter of quality writing at all, what does this tell us about how long it takes to make good writing? If you are thinking to yourself “why, not a goddamned thing! Not a goddamned thing at all!” then congratulations, you’ve landed on truth.
Likewise, it’s not evident that Feast, Spin or OMW would be better or worse if their respective writers took more time or less time to write them. I suspect in each case the writers took as much time as was required to write the novels as well as they could. Before that time the work wasn’t ready; after that, spending any more time fiddling with the text would be like putting lipstick on a pig.
I have a good general idea of how much I can write in an average day, but I don’t find much point in being obsessive about it. Some days I write more, some days I write less, and as long as I don’t have a deadline in a week, that’s fine. I find the most important metric for writing is whether I’m happy with what I’ve written that day. If I am, I’ve written the correct amount, regardless of how many words that amount ends up being. I think this is a good guideline for writers.