Pros
It's a reputable company. There are many very capable scientists. Experiences/recommendations helped me get into graduate school. It's a job.
Cons
Little room for advancement without PhD. As someone with a bachelors degree, I competed for the same job as many with a masters degree. On filling new positions, we struggled to fill roles because those with masters degrees were looking for more than contract work. Not a social environment (at least my location). Competition for project leads often results in scientists unwillingness to share data with other scientists. Very little feedback received on job performance. Work load is feast or famine: I often go 2-3 days of being so busy I skip lunch and then 3-4 weeks of sitting at my desk reading research papers to pass the time. At least at my site, I can count on one hand the number of non-PhD R&D employees that are not contract workers (meaning no benefits, no pay on federal holidays, no sick time, no vacation time - hell I don't even get paid when the company tells me I cannot work due to the snow). As a recent college grad, this is an inconvenience but I can understand and appreciate that I am on the bottom of the totem pole. However many non-PhD employees are 28+ years old with families and advanced degrees, which presents a more serious problem. Finally, this issue results in high turnover in non-PhD positions. Most stay until they have enough experience to achieve a more secure position at another company.