Pros
McDonald's is a traditional, mature organization that is very well run. Strong ethics and business values infuse the organization. Equally, a sane work/life balance is achievable in this organization at fairly high levels of the executive chain. Working for a global brand of McDonald's stature is always challenging and exciting. Salaries are fair, the total compensation package is very good.
Cons
Company is very mature, so getting new thinking and ideas implemented can be a significant challenge (but not impossible). There is not a free flow of ideas and many employees are still reluctant to share their perspectives. General culture is quite friendly but also quite passive-agressive and the organization does not manage conflict particularly well (especially managing up).