Pros
The salary and the benefits are unbeatable. McMaster hires very intelligent people with diverse experiences so you never feel like co-workers aren't pulling their weight. Everyone is held to the high expectations that were made very clear in the interview process, which again makes you feel like everyone is pulling their weight. While the supervisors and managers tend to be the youngest people at the company, they are very professional and great to work with. They are invested in their staff members' growth. This is not the place to work if you want to sit around and talk about your feelings and participate in team building activities. I appreciate the culture of "finish your work and go home". We do take scheduled breaks and lunches, which allows you to make friends and meet other co-workers during the day, but other than those times, the majority of the day is spent at your desk working on your assigned job or task. Most departments don't have a lot of meetings and one of the most refreshing aspects when I started was the lack of email and meetings filling up my Outlook calendar. There are plenty of opportunities to meet with your supervisor and find out how you are doing. In your first year you have 3 reviews complete with steps that spell out how to improve. The success of these meetings can depend on your supervisor but most importantly you. If you are defensive and not willing to improve then obviously they won't go well. If you show your supervisor what steps you are going to take to improve (even if you are already doing well) then the meetings are great. I was once told by a co-worker that the the best thing to do is "stay under the radar", but I disagree. I have been very vocal with my supervisor about what I expect to get out of my role, and what I need from him to continue to grow. So far, making my expectations clear has really worked out for me.
Cons
There is no flexibility in the work schedule but you get better hours with tenure. You have little say in what work you will do, but that is actually a positive because if you are doing well, you will get the opportunity to move around and get a well rounded view of the organization. It is made very clear in the interview process that if you don't come in as a management candidate, it will be a very long time (like 5 years or more) before you will even be able to think about moving into a supervisor role. They aren't as clear however that you may never be considered for roles higher than supervisor. The positive side is that McMaster doesn't care about titles so even if you don't get moved to supervisor, you still can get raises and promotions for moving to different departments and adding more responsibility to your plate.