Pros
Love the upbeat atmosphere and having a great time making people happy. Certainly a lot of potential for personal growth. Teamwork is great and it can really foster a family environment.
Cons
Profit is more important to Potbelly than people. Ultimately, you are judged on results (more specifically how much profit you bring in) over actual performance. If you make the company money, they love you. If things aren't going well despite working 60 hours a week, they will toss you to the curb. Expect to be stretched thin on management and stressed out. They are struggling with growth, as there are not enough people to fill their positions in new shops and they are not concerned with making their employees happy, which is leading to turnover. Many jobs are available for similar compensation and much less work and stress.