Good writing is essential in a dissertation. However, good writing cannot compensate for a paucity of ideas or concepts. Quite the contrary, a clear presentation always exposes weaknesses.
It seems to me that every book reminds me of writing a dissertation.
So, you are preparing to write a Ph.D. dissertation in an experimentalarea of Computer Science. Unless you have written many formal documentsbefore, you are in for a surprise: it's difficult!