Pros
Smart people from good colleges. Easy to make friends within and across teams. I believe that Morningstar does make an effort to hire curious and kind people for the most part. Very flat organization so people across departments are happy to meet with you. 80/20 instituted on some support teams, where one day a week you get to work on a project instead of answering phone calls. Stretch projects are a good way to get exposure to various areas of the company (data, research, HR...) and to take your mind off the monotony of everyday life, but are mostly grunt work projects. You just need to apply to these projects with a brief explanation of your interest and/or prior experience.
Cons
The MDP program is a complete waste of time. The first stint is in support answering phone calls the whole day, where I was told I would spend "6-9 months", which during the orientation period just prior to starting suddenly jumped to "12-14 months" if you have not reached the "competency expected". This is a completely arbitrary decision and dependent on your manager. The freedom to decide when to rotate that the company touts is very misguided and borderline dishonest. Rotating requires applying to jobs within the company and going through several rounds of interviews once again. As a result, rotating does not encourage trying new teams/departments if you are going to be asked about prior experience and demonstrated interest. It is certainly not unusual for people to stay in support for 12 months or longer, which is absolutely ridiculous for a 2 year program that supposedly offered 3 rotations. It most certainly does not in that time frame, except for a tiny minority of MDPs. In addition, getting permission to rotate is just the beginning. You have to wait for a position to be publicly posted within the company to apply. Sometimes these are positions available to MDPs, but you can also apply to jobs available to everyone in the company. Naturally, postings are all competitive so it is not unusual to see people getting rejected several times from rotations, which means you are stuck on support in the meantime. The lack of structure is harmful for the program. I would not recommend this program to anyone. The job drains the energy from participants and does not encourage or reward hard work. If you are a motivated college student looking for meaningful work, I recommend looking anywhere else.