Pros
There's no dress code, and it's easy to make friends. Work hours and vacation time are very flexible. Benefits (including tuition waiver) are excellent. It's easy to rise up the ladder--basically to get promoted, all you need to do is stick around for more than a year and sell your mediocre ideas as innovative. Excellent benefits. There's a pretty easy workload and no work actually gets done. Overall this isn't a bad job to have for a couple years, as long as you don't get too sucked into the culture.
Cons
The pay is way too low. The entire place is incredibly disorganized, which is possibly a result of different departments having totally separate visions and strategies. There's no room for true intellectual disagreement, and the culture can be weirdly negative. Management is poor (as a result of the ease of becoming promoted). It is much more difficult to work here if you are a person of color, a woman, or queer. If you care about actually making a difference in the world, go elsewhere--none of the work IHS does actually makes a difference. People don't have to put a lot of effort into their work, and can get away with being very lazy.