Since you have put this in the business section and because your questions tend to be about business and management and leadership, I will answer in that context.
I do not feel that Covey's book is particularly meaningful. The reason for this is that it seems like a "pop psychology" rehashing of many ideas that already exist in the literature about leadership styles and management styles.
For example, the idea that you should "Put First Things First" simply means that you should prioritize your tasks and plan based on which things are the most important. This is something that any manager already knows. Managers know that it is important to understand what goals are most important to the long-range future of their firm and to plan accordingly.
As another example, the idea that you should "Think Win-Win" simply means that you should seek compromise when possible. This is something that has already been identified as a major component of leadership styles that emphasis compromise and team-building. Covey argues, in essence, that such styles are more effective than more authoritarian styles of management, but this is something that many other people have argued.
Covey's book, then, does not seem like it has new insights for us. He has done a great job of repackaging ideas and making a name (and money) for himself. But academically speaking, it does not seem like a groundbreaking work in management or leadership.