Its difficult to say which book is better , both books have different way of presentation and illustration of concepts. I think a better option will be to refer both. You can also check the Javaranch Book Review section for more details.
K&B book will take you to score 80% in the exam. For rest 20% you need to take a dig into the concepts deeply, for which khalid mughal is apt. I would suggest you to finish K&B first, and then read selective topics from Khalid Mughal which you feel are not there in K&B.