Pros
Caterpillar is a very large world wide organization offering many varied career paths and different opportunities. The product is great and easy to take pride in. The brand is well known, and the company looks good on your resume. Compensation is good, particularly if you're located in central Illinois. If you find a good role and a good organization it can be an exciting and challenging place to work.
Cons
Caterpillar has grown to several times its size when I hired in, but I'm not sure it's handling the transition from a small networking focused company to a large organization. It is struggling to recognize and enable key talent. Good people are not always recognized or rewarded for good work, while sometimes people are rated well and/or promoted just so they can be "gotten rid of." That's not a sustainable process, so it's something they need to work on, as it has resulted in some very questionable in critical management positions.