Pros
Let me first say I have worked for IBM Global Business Services for a relatively long time (8 years). Pros include a fairly good benefits package and decent salary. IBM brand recognition also helps your resume a little, but the brand recognition is for software and servers, not consulting. There is a decent number of fairly intelligent peers you work, although the numbers are declining. It's a good place to go for a year or so to gain technical skills then leave.
Cons
IBM GBS has morphed into one of the poorest run entities in business. Communication is silent within the organization. This is because there is nothing but bad news for employees. Revenue and earnings are growing astronomically while employee raises and bonuses have been trending the opposite direction just as fast. This same pattern has gone on since 2002. This year IBM has decided to skip promotions to save money yet raise what is known as the skill level for promotion qualified employees so they can bill them for more. IBM and its senior management are extremely money hungry and employees are treated like chumps (and you are a chump if you continue to work for such a firm). Its very sad, but you're not a consultant just a person you provides IBM with a source of income. Expect nothing in return. In fact, top rated employees with the highest evaluation rating were recently laid off after being "on the bench" for two weeks.
