Pros
ESRI is overall a decent place to work. The benefits are great and the people who work there are very nice, helpful, creative, and most divisions have a positive team work ethic. If you have a good supervisor, it is a very pleasant work environment with little micro-management, the ability to work on long-term projects, and the opportunity to present new ideas.
Cons
Unfortunately, in many divisions at ESRI, there is a lack of opportunity for career advancement and certain positions have absolutely no career path, contrary to what the recruiters will tell you! Many people who work at ESRI have been in the exact same position for years, and many who are promoted to supervisory positions seem to have gotten there by longevity at the company alone instead of actual leadership capabilities. A common perception is that ESRI has a "flat" corporate structure with few people in leadership positions. Also, job performance is not indicative of salary increases.