I really enjoyed the book, in particular the Objective Negotiation part. I really feel that the book creates a good framework for a negotiator. A good companion book would be The Truth about Negotiations and Getting Past No: Negotiating Your Way from Confrontation to Cooperation.
The other part I really enjoyed was that of one-text, the idea being that for multilateral negotiations or when a 3rd party is needed, the best way is to use one-text that each part can comment on. I did a simulation not too long ago, and had we used this method all parties would have come out with a better agreement.