A brag book can catapult your job search. It's all about marketing yourself. I can't stress that enough. You're marketing a product: you. Market "it" properly, and you'll have one of the most successful job-search campaigns you've ever experienced. Part of the marketing process is to possess high-end career materials; resume, cover letter, brag book, and so on.
Not using a brag book? Wow, you are missing out on an opportunity to set yourself apart from others vying for the same prime positions that you're eyeing. It's about impressing those who have the power to hire you. Did you know that (still!) only a small majority use a brag book although recruiters and hiring managers have said time and time again that they favor candidates who show initiative and offer added value that other candidates do not. It's amazing. In fact, it's a primo opportunity that you're missing out from.
Take the next step by grabbing a copy of "How to Design, Write, and Compile a Quality Brag Book," so you complete a book that will be worthy of being seen and read.