Pros
The company culture is fantastic - people are approachable, the attitudes are positive, there's a lot of energy in every department. Most departments have a great work hard/play hard approach. If you work hard/smart there are good opportunities to move into new roles and advance in the company. NI hires bright, motivated people that want to get things done. NI is also very stable - there's never been a layoff and the company is run in a conservative manner.
Cons
Over time, as the company has grown, some bureaucracy has set in the makes it more difficult to get things done as compared to the past. The bureaucracy is not nearly as bad as many other companies, however. Also, the total compensation package of the company used to be above average and had some unique advantages; however, as the company has grown the overall compensation has become pretty average.