Pros
The pay is excellent for younger people looking to get started and they do promote within from what I had seen while working there. They're generally fair with benefits if it's absolutely your only resource to them and they do offer a decent amount of PTO for their employees. They're also generally agreeable when it comes to missed days and time off so long as you give notice ahead of time.
Cons
As I said, great position for younger folk just starting out, weather or not your supervisors believe that. The real problem with the company falls on the supervisors. It's not ENTIRELY their fault as I believe some just had poor training and were put into positions they weren't entirely ready to take on, however that isn't exactly an excuse because the regular employee suffers from the lack of adequate assistance and understanding. Most just seem over-worked and under-qualified for their position. There's also the extreme issue of favoritism and it seems that some can get away with hardly working while they'll crack down on people who meet their daily quota when they decide you aren't taking the position as seriously as they'd like. It's not a particularly hard or serious job. Most of your work will be simple clerical things and it'll definitely feel more like customer service than anything else they tell you. It's a job at the end of the day, there are good and bad parts and it's no worse than any retail job you can get. Just don't put too many eggs in the 'Express Scripts' basket. It's not a career.