I've read that book and others. NSTD is both extremely good and extremely bad.
TLDR: It's a great book if you can ignore his attitude. And ignore every negative thing he says about Ivy MBA programs and their books. He is simply wrong about them.
The good:
The methods advocated in the book are somewhat "simple" to remember. This is because he focuses on what will work 70-80% of the time, whereas other books tend to also target the remaining scenarios, creating bloat and complex methods.
This is probably the best book when it comes to the psychological aspect of negotiation. The other books do have it, but tend to focus more on the rational aspects.
The bad:
Writing style can be very offputting. An incredible amount of boasting. A lot of it is justified, given he was one of the FBI's top negotiators. But he goes well beyond it. He starts the book describing how he walked into a Harvard class on negotiating and completely dominated the other students with his negotiation prowess. And he goes on and on about how he beat the Harvard students. Really? In my warped view of the world, I thought it was a given that a Harvard student new to negotiations should be able to beat the FBI's top negotiator.
This was beyond pathetic. It's as if Roger Federer wrote a book boasting about how we visited a tennis academy and managed to trounce everyone. What an achievement!
The anti-academic bashing is strong, and quite unjustified. Throughout the book he boasts that his techniques are way better in the real world than what the academics/Ivy schools teach. Umm... no. I read the Ivy school's books before reading this one, and roughly 70-80% of the techniques in NSTD are the same as the ones taught in MBA programs.
I've noted many parts of NSTD where he makes a false claim against the Ivy Books, or where he claims the Ivy Books don't teach Y. One day I intend to write a detailed review on a blog somewhere listing all his claims, and next to each one quoting one of the Ivy Books refuting his claims. It's just very dishonest of the author to criticize other books this way.
(And no, I don't think any of the Ivy Books actually suggest splitting the difference as a good strategy - I recall one even saying it is an option, but mostly if nothing else is working and your BATNA is not good).
Finally, some good books talk about different negotiation strategies based on your relationship with the person. When you don't care about the other person (e.g. haggling in a marketplace), the strategy you would use differs very much from one where you value the relationship (e.g. business partner). He doesn't really distinguish, and it's not surprising given his background where most of his professional negotiations were one-off.
Please be careful when using his tactics with people you want to maintain good relations with. They work well the first few times, but some of them really start to annoy people. One of my managers left our team and was replaced by another one (new to managing). The new manager used some of these techniques, although she had not read the book (especially the continual "How can I do that?" questions). She was relatively successful in the negotiations, but it damaged a lot of relationships. 3 people eventually moved to other teams.
If one is looking for additional books to read, I recommend:
- Bargaining For Advantage (not very prescriptive, but this is the best one to make someone interested in negotiations and want to learn more).
- Getting Past No. You probably should read Getting To Yes before reading it, though. GPN has some overlap with NSTD regarding the psychological side of negotiating.
Getting To Yes is often recommended. It's decent. My only caveat is that it is not as broad as BfA, and because it gets recommended all the time, a lot of people feel GTY is "sufficient". When it fails for them, they abandon the whole discipline thinking they're just not cut out for it.
Not specific to negotiations, but I recommend as well:
- Influence. Many books (including NSTD) invoke this book.
- A good book on communications (e.g. Nonviolent Communications or Crucial Conversations).
A lot of negotiation techniques are derived from these two topics, and they'll make a lot more sense if you've read them.
Finally, regarding salary negotiations, there's actually a really good one in the book, which is the flip of what is usually taught. The conventional wisdom is that if you can't get your desired salary, negotiate on other things (work environment, work from home, hours, vacations, perks). He flipped it around. If it seems they won't match your salary, keep asking for benefits/perks that are somewhat reasonable, but you're confident they can't provide them. The company will usually say "Sorry, we can't provide that perk, would a $x increase in salary do?"
I haven't tried it, but I can see it would work - most large companies have a limited set of variables they can tweak, and cannot customize much for a single employee. So they compensate by increasing the offer.