Pros
Can hide within the large infrastructure. Reasonable pay if you enjoy playing the corporate political games. Good pay if you are in a peripheral role and aren't responsible for actually doing the hands on work (those people get screwed).
Cons
Too big, moves slow, too many meetings, no one wants to make a decision but instead call meetings to get everyone to buy-in so they don't have to take the blame if/when problems arise. Too many layers of overhead and management (people managers, project manager, program managers, etc, etc). Keep pay low by out-sourcing, off-shoring and using vendors for lots of positions, departments and functions - this rips at the shared fabric of Dell success and undermines the control Dell employees have over their own future/stability. The same problems come up on every project, lots of pressure, stress, tension, finally management engages, pulls extra resources in to get things back on plan, cut features (or fix them with update post-release), lower severity of outstanding issues and plow forward. Rinse, repeat.