worth doing
yeah, where you do your instructor rating is key.
If its a busy school, chances are you will get put on as a casual g3. More chance to get a job where you do it because they know you and your attitude/skill etc etc.
Its worth doing, but dont expect a job by being a lazy bare minimum effort person. put some effort into it. I loved instructing but it does do your head in after a few years especially if you dont get into twin or ifr stuff.
really make an effort to think about how you can link the subject matter to the students given there age/education/experience level in a manner that is normal and easy to grasp! :-) good luck