There are many things that artists say that could be absolutely absurd are equally true depending on the context. I've met people who believe that "art" must be organic. It should flow like a living organism through time and space, growing when it will, revealing itself to the world in a manner natural to its own existence. I could go off on a long tangent about that, but this post is about something different.
Deadlines aside, when it comes time to make revisions, deep edits, and final polish, rushing the job could be one of the most disastrous decisions a writer can make. As I mentioned last week, I'm in the middle of writing a character out of my book. He's more entrenched than I originally thought, and this is taking more time that I'd planned. And aside from the "life" stuff that's kept me from making progress, I'm doing what I can to slow down and make sure I make these changes correctly, smoothly, and with as much delicacy as possible to keep the rest of the story intact.
You see, if I were to search-and-delete every instance of this character's name and then just replace it with a character that will remain, the rewrite would take minutes. But think about how clunky that would feel. Just imagine a simple dialogue scene where four characters WERE standing around talking, and suddenly there's only three. And one character is replying to something he just said, but in the "voice" of a character who no longer exists.
Now imagine an action scene where one character saves the day and the replaced character might've gotten hit in the head, leading the first character TO save the day. The first character won't save the day because he's suddenly unconscious.
So when you sit down to work on your rewrites, always make sure you're purposeful. Take your time (but don't procrastinate or waste time!). Rushing is for the first draft. That is the race to the end. But the slow, clean polish the second and third time around is where you turn that rough draft into a masterpiece. It's not guiding a bonsai tree to perfection, but it is developing a story that agents, editors, and–ultimately–readers want to spend their time on.