This advice seems obvious: always trust your gut. And, I'll bet it's the advice you will have the hardest time heeding as you prepare and grow your portfolio.
Every single person you show your book to will have a different opinion about your book. I may absolutely love your long-form, stream-of-consciousness copy for the ADHD Foundation and the very next person may hate it. So, so, so many times at an Ad School portfolio show I will be commenting on someone's book and they'll tell me the previous person told them the exact opposite. I say leave this work in, another recruiter will say take it out. I love your logos, another will think they really suck. Well, they'll say it much nicer than that, but you get the gist.
So, above all else, do what feels right to you. If you love the piece that 5 out of 8 recruiters hate, leave it in. Just make sure you can elaborate on why you love it so much. Even if I am not loving a particular piece in your book, if you proceed to tell me the reasons why you feel strongly about it, I will cut it some slack. I love hearing stories about people's work. It means so much more to me to learn about your passion for advertising than it does to love every single piece in your portfolio. Cuz chances are I won't. But I will tell you my honest opinion (thoughtfully disguising the word 'suck' of course) and that gives you the grounds to decide whether or not to take it.