Pros
Fantastic group of people to work with.
Exciting market to work in.
Tech company level benefits (catered lunches, excellent insurance packages).
When the product and service worked(!), clients were truly excited at the efficiencies gained.
Cons
Corrosive middle-management style (read: witnessed some petty, immature behavior towards subordinates that I was surprised to see in the work-place).
Found middle-management to be disingenuous at best, two-faced at worst.
Saw groups of people laid off/fired--horrible for moral.
No actual internal HR department. If you experience something that should be brought to HR your actual recourse is to either quit or try to transfer to another group in the hopes you can avoid the toxic person(s).
Often encountered resistance from my direct supervisor and our group manager when attempting to fulfill what, I thought, was my job description (part of job title no less). Wish I had that clarity from supervisor from the beginning, would have avoided conflict and misalignment of expectations.