Currently I am a graduate teaching assistant through the CUNY graduate program. However, from 2009 to 2011 I was an adjunct at QC. I love teaching and don't have any major issues there, but a major factor which pushed me to join the doctoral program was a lack of job security as an adjunct.
I was teaching semester to semester and felt myself very lucky if some other teacher dropped out of teaching just before the semester began so that I would be able to get a second class. On the other hand, only knowing what class I'm teaching mere weeks before classes start is somewhat stressful and certainly not something I like, but it is part of the adjunct's teaching life.
I realized quickly that in order to have any sort of long term stable teaching position, I needed a faculty job, thus I abandoned adjuncting and joined the doctoral program at CUNY. I am still able to teach but now I am on a tract that will get me out of the unstable lifestyle of an adjunct.