Pros
I have had many (25) good years with IBM. I've worked with real good people, invested in their jobs and the success of their projects. There is opportunity at IBM to move around and have many different experiences. I've worked on over half a dozen projects in those years and in a variety of capacities. Decent benefits including flex time and sick leave. Every direct manager I've had cared about his/her employees and giving flexibility when 'real life' issues arose.
Cons
This isn't the old IBM. Now, like any other company, to hang on and avoid layoff you need to acquire and maintain relevant skills and are responsible for your own future. And you also need a certain amount of luck to not be on the wrong project at the wrong time. Strives to be 'middle of the road' compensation wise.