Pros
Get to see a variety of cases, as well as a variety of doctors. Hands-on skills with Epic EHR and general charting process becomes well developed. Some doctors are easier to work with than others, but that eventually isn't an issue as you eventually meet all the attendings.
Cons
Emergency department is generally fast-paced, so there is not much time to ask questions and learn about the field (beyond clarification questions) Because you are assigned shifts/doctors, it's hard to develop actual relationships with the attendings / other medical staff. Overtime pay is usually limited to an hour, so if you aren't able to keep up with the pace of the emergency department (my typing speed is about 120wpm for some context) it can be stressful. Low pay, do for experience