Pros
IBM is a large company that used to be very stable. Many of the people are very intelligent and friendly. Unfortunately, these people of ability are not often promoted to senior management positions unless they have very good contacts and know how to play corporate politics with the best.
Cons
There are many. (1) Wages at IBM are approximately 75% to 80% that of similar positions in other companies. I found it amazing that in fiscal year 2007-2008, a year of exceptional profits, IBM found the money to double its dividend, but not any money to give rases to employees from the job family: US based IT technicians and project managers. It is interesting to note that EXECUTIVE pay and performance bonuses increased by a high percentage in 2008. (2) Professional growth is limited by frequent funding freezes that preclude the attendance of training seminars and graduate level education. (3) Some departments have a minimum overtime requirement of 20% or higher. (4) The system used by the company to rate its employee's job performance is broken. Time away from work is counted against you, even if you have a valid reason for being away. For example, if you take a 4 month leave of absence to care for a sick relative, when you return to work, your work contributions for 8 months of work are compared to a coworker's contributions who has been working the entire year. It is virtually impossible to get a good job performance evaluation at that point. (5) Work/Life balance is given lip service because it becomes almost impossible to take a vacation when you have a high overtime requirement and vacation or sick leave (Time away) counts against you. (6) Morale at IBM is very low and many people are leaving voluntarily to find jobs in companies that treat their employees better.