Pros
To succeed at IBM, you need to be entrepreneurial and take initiative. If you sit around and wait for someone to tell you what to do and how to do it, you might not like the results. If you have a vision, are a good communicator, and don't mind putting in the elbow grease, then you can have a lot of fun building out programs, products and technologies (depending on your skillset) that have the potential to affect a great many people and industries.
Cons
If you're a pessimist, you'll probably focus on how long it can sometimes take to see progress. It does take patience and vigilance. It's a big ship to turn, so it might be especially difficult for people coming in early in their career or from a small business or startup environment. It's all a matter of perspective. I also think the HR practices are a bit outdated, but that doesn't affect most people's day to day life. Another issue that has come up more recently is the sheer volume of new hires from the outside not being vetted sufficiently for a fit with culture and values. It's great to have a lot of fresh thinking, but it's hard to tell who has integrity, who can deliver in this complex environment, and who is just a stuffed shirt.
