Eventually must be comfortable being part of a machine
Pros
The most inspirational work you can ever hope to find. Facilities and environment is fantastic. Support to employees is phenomenal. 401k matching, Health, educational services are bar none. Regular grants in cash and RSUs for performance. Staying at the company long-term has phenomenal benefits. Co-workers are all highly motivated interesting individuals who are often a great pleasure to be around and learn from. Everybody is (generally) happy and proud to be there, to do the work they do.
Cons
As with any company, not all work is purely inspirational and awesome. Eventually there will be monotonous drudge work. Eventually there will be politics and they may not play to you. This is to be expected with any company, especially a large company. Part of the magic of apple is that there are many autonomous groups. Your experience at Apple will depend largely on which group you find yourself in. There are great groups, and there are not-so-great groups. You may or may not find all of the bad situations you may imagine or have encountered elsewhere within these groups. You may not have much recourse against it, short of risky politics of going over your boss. HR typically does not engage in low level politics and primarily exists to protect the company from lawsuits (as with any large company).