Pros
Good starting point for fresh-outs and few years of experience people. In general: good work environment, laid back culture, conscientious about work/personal life balance. If you have the connections with management, sure you'll have a good career in NOV. Job security.
Cons
Limited career opportunity, even though it's a very large company, there's almost no cross divisional transfers. Lack of an objective performance evaluation system to promote the most capable personnel. Many people get promoted/given opportunity based on how the bosses like them (subjective). Salary all over the place, depends on employee's negotiation skills and leverage position. Average salary lower than industry's. Inefficient, don't know how to fix root cause's problem, everything wants to be solved with money, either increasing headcount or buying competitors. Falling behind the competition in the long run. There's a complete lack of synergy among all the divisions. Too much politics in the everyday work.