I've sent the first half of my "representative chapter" in so they can get a feel for what I am trying to do. I suppose that this could make or break the book. For all I know, they could read what I've put together, have a "polite" conversation with my agent and it will all be over. I don't expect that my writing is that bad, but I did notice that my conversational style does not match that of my coauthor. In fact, I can't help by use my patented Ovidian humor, so something is going to have to give.
I write quite a bit, so I shouldn't have been too surprised, but all of my writing work over the weekend was, after I properly formatted the pages, reduced to about 8.5 pages to text (how's that for excessive commas? You won't see that in the book :). I'm going to have to work even harder than I thought to get something out in a reasonable amount of time. I also found myself doing a fair amount of research on topics that never make it into the chapter. I had a brilliant (ha!) paragraph about a 19th century Italian economist whose work perfectly illustrates productivity issues that arise during programming, but needless to say, I struck that paragraph after rereading it.
I also found myself wondering if 1/3 == 1/3 is always true. Floating point math is tricky, so I certainly didn't want to mislead anyone, but it was peripheral to what I was doing so I didn't delve into it too much. Hmm ... more research.
A lifetime ago, when I was studying music composition (who thought I had a CS degree?), I heard an interview with Quincy Jones. He was talking about the composition process. The important thing, he said, is that you don't stop to say "That note's wrong, that lyric is bad." Just write. Edit later.
A good editor will smooth out differences in tone. A good editor will distinguish the fluff from the meat. Just write.
(Run your outline by a good editor first. Just Writing is easier with the right outline.)