Users can easily comprehend your plan because it is organized based on things that they do. Because use cases describe fundamental business functionality, your developers learn the business while they implement use cases. Reuse becomes more difficult because commonality between use cases may not be recognized until late in the project. Senior management can have difficulty accepting the approach if they are not familiar with use cases. Developers like it because it doesn't require significant knowledge of how the system is used.
Management likes it because it is more along the lines of traditional planning.
Reuse is easier to achieve because common features may be developed early in the project. The main disadvantage of this approach is that it is much more difficult to guarantee that you will deliver value to your users in the order that they need it. Users can easily comprehend your plan because it is organized based on things that they can see. Developers like it because it doesn't require significant knowledge of how the system is used. Management likes it because it is more along the lines of traditional planning.