Pros
They are a very large company with a long history in the chemical industry. DuPont has it's finger in also every branch of the chemical industry, leading to many opportunities and variety of work assignments. Most everyone I have meet so far has been very hardworking and knowledgeable providing support to their colleagues. The name DuPont carries a strong reputation which is good in my opinion. They also appear to be constantly changing with the changing economy focus like the focus on 'greener' products which is exciting to witness/be a part of.
Cons
Also because it is such a large company it can be frustrating working with much of the restrictions needed to organize and maintain security and connectivity of the company. Communication is also not a strong point of this large company. I have met some disgruntled senior employees who have been with the company for over 20 years that aren't pleased with the way the company handles pension plans and the retirement of their colleagues.