What I used to like the most was just working on planes. Loved doing it. What I dislike the most is the pressure to do thinks the cheap way. More and more pressure to save money, not do something till next check. The job is very challenging. Planes are getting older so more troubleshooting needed, and as stated above, more pressure to do things faster / cheaper. Lots of opportunities to learn. Very little opportunity to advance.
What keeps me in it? I can't afford to change careers! Most of the mechanics I know that have 5, 10,15, or more years in, all say they wished they chose a different field. Just look at the history of the major airlines. Hiring, layoffs, call backs, layoffs, call backs, layoffs. I have been fortunate enough to have never been laid off. But lots of my friends have. Hard to keep a family when you don't know if your going to have a steady job!!!