Clinical Data Manager or Clinical Project Manager?

I am a Senior Clinical Data Mgr. and I have the opportunity to become a Clinical Proj Mgr. I have an MSc degree. Could someone explain the opportunities that both positions would provide? The Clinical Proj Mgr. seems to oversee how a study moves along by communicating between investigators, sponsors, monitors, along with some involvement in the development of the protocol. Have I understood the the project mgr. role correctly? Could the project mgr. job lead to other higher chances (perhaps management) in Clin Res. at a pharmaceutical company, or would a Senior Data Mgr. role offer more of a steady dependable (grunt work) job? There seems to be slightly more of a need for data mgrs. at the moment. What position pays more money per hour as a contractor, and as a permanent job? Do contract proj. mgr. jobs pay better than contract data mgr jobs? I don't want to lose data mgmt. skills if a project mgr job has no steady future and makes less money. What job is higher up the ladder?