Advantages might include:

Doing a job that really matters

Having a positive input in to current issues

Taking responsibility early

Seeing the practical impact of your work take effect

The satisfaction of having an impact on the way people live, hopefully for the better

Whatever the disadvantages are they must obviously not dissuade you from the job! They might include:

Decisions you make could have repercussions which you had not intended.

The work entails a good deal of pressure and stress.

You may have to work long hours

Many people are counting on you to do a good job

One becomes very job-focused (could also be an advantage!)