Pros
There is a kool-aid most drink, they call it culture. While it is corny, I've observed that majority of folks do try to adhere to the culture of "Treat People Right, Get It Right, Do The Right Thing"
The pay isn't on par with bigger consulting firms (not far off), but the coaching is better
Flexible on where you work, PTO policy is nice
Cons
The hours are tough. You might coast for a bit, but if you want to climb you will need to pay your dues eventually. Typically Consultant and Manager role is the busiest.
The 401K match is laughable, other smaller perks try to make up for it, but honestly not great other than insurance. Health insurance is amazing.
The bad apples that have made their way up are going to manage you at some point or another. Some people climbed up strictly on numbers, and forgot about the people component. ZS does not do enough to punish these people because they get results through making you miserable.