How does it compare to this one? 
Discussion
Never split the difference is a great book!
Voss’ book is excellent. I see it as a modern contemporary to this classic.
In sales, a No is sometimes more valuable than a Yes.
I didn’t love this book.
Trying to sell to an unqualified buyer by shooting for a “yes” can be the biggest waste of time on the planet.
I always shot for No’s as quickly as possible. Then we can work on Yes.
“Well Ok, Tony Robbins. I just wanted some chicken wings”.
Both are excellent.
Cohen is less about psychological techniques & more about setting goals, gaining agreement while not being invested to the point of life & death. Caring about the outcome but you won’t blow your head off if it doesn’t work out. Softer approach in a way if that makes sense.
Voss is deep into unbelievable psychological analysis on mirroring techniques, empathy etc & due to the nature of his work; it typically was life/death type stuff. Harder approach.
Ironically, The net net of anything is that you have to be genuine & be yourself. I’ve done software sales for 25+ years & the ones that are the best (long term) are extremely smart & very genuine to themselves whether that be a softer approach or hard ass dickhead :). You are who you are. Be that.