Pros
My R and D job at IFF (and I believe this is not just my experience) was interesting and dynamic. I had plenty of opportunities to learn about different parts of the company and get involved in projects that impact different parts of the business. Innovative research is the rule, not an exception. Most people manage to maintain a good work-life balance (although many top performers work much more than 40 hours) and summer hours.
Kontras
Career growth occurs slowly and often depends on the number of years worked rather than performance. Once your manager puts in for a promotion, you will wait for a year or longer before it gets approved. Salary growth is also slow -- so make sure to use a good fact-based source (h1bdata.info) when negotiating.