Pros
Many diverse, interesting technologies and products to work on and contribute to their success. Intelligent, motivated colleagues who were very professional and ethical. Flexibility to work from home. Great education opportunities. A good company to gain industry experience, just do not plan to make it a career.
Cons
Management decisions to dramatically change compensation packages over the past 15 years and significantly reduce the North American work force has damaged the morale of most IBMers who remain with the company. Not a surprise that IBM dropped out of the Fortune's "100 Best Companies to work for" about 7 years ago based on their growth strategy impact on morale. Top executives reap the rewards of severe cost cutting to meet Wall Street expectations, but this is not a strategy that can last forever. The old culture of being an IBMer used to mean the company expected the employee to do anything for the company 24/7/365, and the employee responded and was motivated to do so because of the culture of trust since IBM took care of ALL of their employees, not just the ones at the top. Sadly, those days are history. Still a lot of good people there hanging on trying to make a difference.