At our leadership trainings, we have learnt that it is more rewarding to be a leader, than manager. While a leader is smart, caring and flexible to change, the manager is often quite rigid and instruction specific and may not have the ability to manage change. This is due to managerial approach of guiding a team through a set of instruction to deliver a task without interplay of the human characteristics such as physical capability, mental ability, emotional development, social and interpersonal skills of team members. This could lead to the underachievement of such teams.
10 differences between leaders and managers http://www.youtube.com/watch?v=8ubRzzirRKs