Pros
IBM is one of the biggest companies in the world: if you're in, and you're able to sneak well through it, you can virtually experience every kind of job you're interested in.
Cons
The code word is "chance", at least for my experience as a business consultant: if the timing is right, you're not overstaffed and your manager is available to support you (I say "available" and it's not a mistake: sometimes managers in IBM look so busy to listen to their collaborators) then you are allocated to cool projects on cool clients and you can make your way. If one or more of this perfect storm of factors do not occur then you may stay at your desk without a project until someone comes and tells you're idle and a solution must be found. Usually the next step is that you are taken and allocated to a giant project (no matter which one), it comes out that you have not the skills required (because nobody spent five minutes looking at your resume) and the ultimate outcome is twofold: 1) you keep on working on this project getting more and more frustrated, or 2) you ask your manager to be ousted, so he will give you a bad evaluation at the and of the year, you go back to your desk and history repeats.
