Pros
Good benefits package. The technologies are interesting and there is great potential to combine 3M technologies to create new products and markets.
Cons
There is a undervaluation of technical expertise at 3M. People who spend an inordinate portion of their time making Powerpoint presentations for upper management advance and those who make massive technical contributions see their careers stagnate. 3M management lets the tail wag the dog in pushing the quality initiative de jour so pervasively that it greatly impedes progress and development. The company reacts to change at a glacial pace and fails to react quickly when markets change. They empire build and then resort to layoffs and write-offs once the tide changes and they've missed the boat.