I once wrote a fantasy novel with a partner three states away. It was enlightening and eye opening to say the least. We at least had the plot all hammered out and had divided it up into two teams. We'd alternate chapters. Hers were always better polished. Our writing styles didn't mesh well either. I've always had a tendency to write in short sentences that were pretty much point black and to the point. She would spend more time on her words. Where I'd say "Joe looked down." She'd write "The canvas of the world spread before him as Joe looked down into the mouth of the earth."
Or something like that. Well, nothing like that - - but you get the point