Pros
Being a new graduate, I find IBM has been an ideal place to begin my career. The salary is competitive, career paths are clearly defined, and the growth opportunities are prevalent. IBM uses a lot of its own web 2.0 corporate software technologies to help employees connect to each other internally. This makes knowledge sharing a lot easier and has been an invaluable resource in helping me get up to speed with my new job.
I also happen to work for a team and brand that is wonderfully managed - which makes all the difference when it comes to work morale. The flexible work environment and the globally diverse nature of the employees at IBM is definitely a huge plus. There are numerous networking, mentoring, and training programs in place to help employees progress up the corporate ladder. Being a female employee, I find that IBM is extremely accommodating with regards to things like generous maternity leaves, options to work part-time, and with the rising gas prices, the option to telecommute or work from home. The hours are not rigorous at all and very reasonable, making work/life balance a lot easier. I really like the fact that my position is challenging yet has clearly defined roles and responsibilities and I don't have to juggle 5 different hats like I did with a previous small company I worked with. IBM also rewards top contributers and performers, and automatically adjusts salaries on market-based references.
One more thing that I love about IBM is that it is a very environmentally conscious company. There is a big push towards using green data centers, and the software lab I work at has won numerous energy awards for conservation.
People generally view IBM as an 'old' and 'boring' company when compared to the newer kids on the block like Google and facebook. I can't comment on those companies, because I have never personally worked for them. However, that being said, IBM in my opinion is by far the most innovative out of the big five and is the only company that has truly withstood the longest and hardest test of time. The company continues to grow and reinvent themselves at the turn of every new technological revolution, and embraces change and research. It's definitely a lot more stable and secure company to work for than the other big five and the company learns from its competitors and adapts accordingly. Surprisingly, IBM has many of the perks that Google and Yahoo! and other companies do, such as on-site cafeteria, fitness center, games rooms, relaxation rooms and much much more, however these aspects are not as well marketed online due to IBM's lack of presence on the online scene.
Cons
Since I am a new comer to the scene, the excitement of working here has prevented me from seeing many downsides to working here at the moment. One thing is for sure though, IBM is not for those who like the thrill and challenge of working at small company start-ups where everyone knows each other. It takes time to implement new processes and products here, and the turnaround time can be very long. There is also still room for improvement in terms of connecting employees across the company, however I feel they are headed in the right direction.
The managers are very busy here and sometimes it can be difficult to get the answers you need because almost every policy or process begins with "If in doubt, consult your manager" and most of the time I end up spending too much time figuring things out myself.