Pros
General Mills "walks the walk". Excellent career development, great leaders at both the corporate and manufacturing facilities, superior work-life balance, and senior leaders who are not only easily accessible, but who listen and recognize outstanding performance.
Employees - Virtually everyone is top notch and brings something to the table
Ethics/Integrity - General Mills jealously guards their reputation and is highly ethical
Products - Great products with a focus on making them healthier
Community - Give back is an understatement
Pay/Benefits - On par, if not better, than peer CPG companies
Senior Leaders- World-class, always available, hires the best
Continuing education - GMI offers classes internally as well as supports their employees taking external classes
Respect - Leaders/managers respect and recognize the hard work of their employees
Productivity - The company continues to increase productivity without reducing headcount
Pension - GMI is one of the few companies left that continue to offer full retirement pensions on top of a matching 401k
HQ - Full service cafe, Caribou, salon, on-site fitness, coffee, healthy snack bar, lectures from world renown experts in all fields, beautiful campus
Cons
Really no downsides. I have read other reviews and the common "con" theme is the promotional process. Yes, it can be frustrating and can be political, but all in all, there are a limited number of positions the higher your level which can limit those that deserve to be at higher salary grades who are not. The grass always looks greeener on the other side. I've know many who leave the company for a $20,000 bump in salary and end up coming back because the the grass really wasn't greener.
Other: Conference rooms can be very difficult to find last minute. However, the large seating in the cafeteria is always available and ample.