Pros
Anyone who is looking to break into the airline industry, or gain additional experience with one of the industry's "big 6," will find United as a viable option, albeit for some quite jarring reasons: Because of United's increasingly toxic employee and customer relations, voluntary and forced turnover rates are quite high and the barriers to entry and advancement are very low. Disciplined individuals who can maintain professionalism, composure, and objectivity in the midst of a rigid, top-down, and often unhappy work environment will find the negative lessons learned to be very valuable in follow-on engagements, especially with other airlines.
Cons
United Airlines is plagued everywhere with factionalism, mistrust, and adversarial relationships between customers, suppliers, the C-suite, and employees. Employees and customers are not valued and they know it. Leadership exists in but a few, silo-ed pockets; executive and middle management layers are entirely too self-absorbed. The company's current strategic direction -- to reduce costs by every means possible (primarily layoffs, outsourcing, and attrition) in order to generate cash, executive bonuses, and the holy grail of a merger opportunity -- has created an empty shell of a company that once had a big heart for customers and employees alike. Strategic planning is largely ineffective and tactical implementations are often realized late or not at all. Planners, project managers, and older employees are regularly purged in every furlough event. There is no agile, innovative, creative center of gravity anywhere in the company. United wisely began implementation of an Air Canada-style Lean Six Sigma transformation effort in 2006, but decapitated the program in 2008 and has been scaling back expectations ever since. The primary computer systems undergirding every facet of the business are of 50s, 60s, and 70s vintage; everything about how the business operates is tired, cranky, overly complex, and poorly documented.