Pros
I worked at JimmyJohn's during my last few years of high school and first few years of college. It was honestly super fun and laid back. Everyone at my location became best friends, and we hung out all the time after work. I like fast-paced work, so I did not mind the busy weekends. The managers were great. Best of all, I met my current fiance working there.
Cons
Can be slow in the evenings (at least at my location) which was boring. Low pay for in-shoppers, which is to be expected because it is supposed to be a first-time job for kids. The drivers were usually older though and actually made a decent amount of money. I was upset with a manager who scheduled me to work from 7am-10:30 pm on Sundays after I told him I didn't want to, but I was training to be a PIC, so I dealt with it. Also, like many fast food places, it was constantly understaffed, so there were some weeks I worked 50-60 hours while not even being a manager! But, getting that overtime check always feels good.