Pros
Interesting work, attending events, cool co-workers, personal workspace
Cons
They don't care about your work-life balance. You will be forced to work essentially 9 hours a day for the pay of 8 hours a day. If you don't want to work after hours or on weekends they'll make you feel bad about it. They only care about work and working. Zero flexibility on hours. They want your work to come before your life. If you're a workaholic who's entire personal identity is their job, then you'll love it here. If you want to have a life outside work, maybe not. Most people who get promotions have to hand in their two weeks, then in order to keep them MainGate will offer them a promotion. Otherwise I didn't see promotions happening. They also don't pay very well either. You'll make more in similar positions elsewhere.