Then, after the speed writing is done, if the result is to be published, I usually spend another 30 minutes poring over every word and polishing it up.
The result is something people find reasonably pleasurable to read and I don't agonize over for hours wasting time.
Also, I find myself doing a lot of in-situ editing, as the article suggests. But rarely have I found that it's fully sufficient for work I really care about. And therein lies the rub: for 99% of my daily writing, the burst method works near-flawlessly. But for anything that I want to stand the test of time, a.k.a. publishable fiction or academic work, I will give the revision its fair course (and then some).
At the end of the internship, he asked me what I thought of the script. And I found myself able to speak with candor, precision, and something approaching intimacy about the way it had evolved over the months I had seen it. At that point I realized that he had basically Miyagi-ed me. Wax on, wax off. Paint the fence. Etc. It was a humbling, but (in retrospect) cool experience.
The thing is, different writers have different modes of writing. Some are wholly capable of producing, in spans of 15 to 20 minutes, perfectly serviceable content on any topic imaginable. Others pore over every word, agonizing for possibly days on end. Nabokov, for instance, fell into that latter category; he was notoriously slow and picky about his construction, and his daily bursts sometimes yielded a sentence or two at most. Yet I doubt there's a credible critic around who would assail the beauty of Nabokov's results, or claim that he wanted for practice.