It depends. Cons for one person would be pros for someone else. Have you done observation in both settings? If not, I'd suggest doing that, so you can decide for yourself what's a pro/con in each setting. Some people love outpatient because it's a nice consistent schedule (patients every half hour or hour, whereas a hospital you're floating around a bit, waiting for patients to come back from tests, etc), but others find that dull/boring. Some people love the complexity of inpatient because there are other medical problems to deal with (dialysis, EKGs, respiratory problems, open wounds, etc.), while other people would rather not deal with that and just want to focus on rehabbing the ACL and not have to worry as much with monitors and other medical issues.
It really depends on the person.