What are the major advantages of using EVM as a project control mechanism? What do you perceive are its disadvantages?

The major advantages of EVM are that it is a comprehensive approach to measuring progress (links cost, time and completion), its use of objective criteria, and it enables more accurate information for decision making.  Disadvantages may include the time consuming nature of analysis in large scale projects, mathematical formulas used for efficiency do not take into account unique problems that stall the project or spike costs in one area (which may not lead to overall poor efficiency), and a lack of information regarding what type of corrective action may need to be taken.