Pros
IBMers are eager to help each other and share knowledge about best practices and how to be effective in your job role. There is a culture of teamwork, where people will take the time to help even if they are not getting directly measured on the issue at hand. IBM also have a good work/life balance where they promote working at home and managing one's own time as long as the job is getting done. IBM management has done a very good job of adjusting the business based on the projections for the future coming out of research. We spun off our PC business in 2004 (?), way before the PC market became soft, and invested in software products that help customers reduce their operating costs by "doing more with less." These decisions have enabled IBM to grow revenue and profit in a tough economy.
Cons
IBM used to be a sales led organization. Now it is very much led by finance. All decisions and systems that support compensation, expense, investment, etc. are designed to closely manage costs and tie the employees hands when it comes to travel, customer entertainment, sales commission/bonus, and other costs of doing the job.