Pros
There are many different groups within IBM so it is often easy to move about if you want to change your technical focus--not many places can offer hardware, software and consulting work. They are also quite accepting of your working from home and flexible with vacation time. From what I can tell for Austin, IBM pays a competitive salary and some of the benefits are great (the 401k matching in particular). If you are recognized as doing a better job than most, you'll get monetary awards through out the project. If you steadily contribue and try hard you'll be able to climb the ladder and be well compensated.
Cons
IBM is a massive bureaucracy. I imagine only working for the government or defense companies could be worse in terms of overhead. Process, process, process. If you come from a startup culture, you will almost definitely be displeased with it. And because of the process overhead, so often you'll churn your time not doing anything productive. IBM also has the typical problem of promoting its engineers to their lowest level of incompetency. I guess that is good for the individual but not good for the engineer. Just because you are good at coding something doesn't mean you should be an architect. I'd rather see focus on salary raises for those that are great at their job and less focus on promoting beyond their skill set. I see too many architects that don't make good decisions because they were promoted too quickly.
