Pros
I worked at Morningstar for over 10 years and saw the company evolve from a true start-up to a maturing, global business. What made the company great in the early-mid 90s no longer sets it a part from the companies of today, however the ability to forge your own path is still attractive if you're an individual who can take initiative, network with the right people, and not wait for someone to offer you what you want in terms of more experience. The flexible schedule is the real standout in terms of strong Pros - very few companies get that people are not children and if you treat adults like professionals and expect them to manage their time and take ownership of their work, they'll deliver and you can avoid a 'clock in, clock out' mentality that comes with a paternalistic approach to vacation/sick time.
Cons
Executive management consists of folks who have been at the company 16+ years and it is starting to show in a negative way - lack of focus in terms of direction and vision, inability to commit to certain goals in a tangible way (e.g. put the resources against the products that have the most potential for growth and kill the ones that don't make money) and aversion to the types of calculated risks that will be necessary to avoid Morningstar from becoming another Value Line. Many folks mention a 'flat hierarchy' and while that can be helpful, I think it's starting to work against the company. The people in the executive ranks have made their millions; the middle managers and their teams who are the ones cranking out all the work get paid below market wages but are expected to do the job of 3+ people. Burn out is common and if you're good at your job, the expectations keep getting higher. No mentoring for managers and no career path development. HR is a disappointment - while the HR management claims to care about employees and the desire to be transparent, an initiative in 2012 to address salary concerns went no where and died after several months.