Pros
IBM is still a leader in many technological fields, and can be an excellent place to build your skills and confidence as a developer. There is also a concentration of raw brainpower in certain parts of the company which would be difficult to find elsewhere - which can be a challenge just to keep up with, but also makes possible undertakings that few companies would dare attempt (much less pull off successfully). So while a job at IBM is not a "career for life" in the way it once was, it certainly can be a good starting point for your career. And once you've been an IBMer you will find you are always an IBMer (and that a lot of the tech world is just now catching up to things that IBM had figured out decades ago). Also, while the work/life balance sometimes leaves too little room for the "life" side of the equation, most parts of the company are at least very flexible about when and where your work is done.
Kontras
Upper management lacks any genuine concern for the company culture or quality of its offerings - having turned to ugly financial manipulations to prop up its P/E ratio where once IBM's business and valuation was built on its loyal workerforce, reputation for service, and superior technology. You will make friends with good people and then have to console them through being victims of arbitrary cuts because the executive "leadership" at IBM seems to need someone (other than themselves, of course) to fall on the sword when there is an earnings miss. Compensation leaves something to be desired, as do opportunities for advancement when positions are being eliminated ahead of you rather than opening as vacancies that need to be filled. Less than a year after leaving IBM for a startup, I'm earning more than twice what I did at IBM and filling a much broader role than was available to me in my old department. ...that said, the skills (both technological and political) I developed at IBM have been critical to my success since leaving. So it's not a bad deal if you think of it as a wallet-friendly, hands-on alternative to graduate school (and make sure you're putting in enough effort to walk away with both you and the team you worked with feeling there's something to show for the time you spent there).
