Over years, I have been on both the sides, management, and development, in software companies. These methodologies are guidelines, and to be tweaked based on the company culture, team dynamics etc. For me, successful implementation of the methodology is when I looked beyond the planning & reporting aspect of teams. Important questions are, Do you have distributed teams vs collocated teams? The maturity of the team members, years of experiences in IT, working together? current collaboration and communication challenges between team members, intra teams and teams and management? If you spend time in analyzing these questions, you have good chance of success.