Ghostwriting is fun.....plus work. The worst part is not that your name is not on the book, but the lack of independance at times.
I have had clients who gave me a mere 10 words brief for a 500 page book and others who questioned each word. The fact that I managed to work out all of them satisfactorily (theirs and mine) felt great.
Every book poses questions on how to work out the details, but the point to remember while ghostwriting is that your name is not on the cover.....so it should not sound like you. To be able to do that while maintaining your love for the written word is essential.
There are thousands of articles on how to represent the client, to base the book on their thoughts and their style, yet the art of camouflaging your words and morphing their words into your paragraphs requires constant work and unflagging attention to detail.