Drawing on a 1-year application design, implementation and evaluation experience, this paper examines how engaging users in the early design phases of a software application is tightly bound to the success of that application in use. Through the comparison between two different approaches to collaborative application design (namely, user-centered vs participatory), we reveal how sensitivity to the role that users may play during that collaborative practice rebounds to a good level of user satisfaction during the evaluation process. Our paper also contributes to conversations and reflections on the differences between those two design approaches, while providing evidences that the participatory approach may better sensitize designers to issues of users' satisfaction. We finally offer our study as a resource and a methodology for recognizing and understanding the role of active users during a process of development of a software application.