Pros
Most people are willing to do whatever is necessary to see the company succeed. Good compensation, decent benefits. Relatively flat management structure, but there's plenty of room for growth if you're a software engineer. Work/life balance is totally dependent upon which group you work in, and what projects you work on. It's fantastic in some groups and completely sucks in others.
Cons
Lots of changes since the DTCC acquisition. Can be very political, depending on your department. There are some departments that seem to be shielded from having to perform at the same level as others. Performance evaluation within departments is based on a bell curve; bad news if you're part of a highly performing team. While the company seems to be trying to provide transparency, there have been some serious gaffs in the past couple of months. Overall, people are still concerned about how the DTCC transition will play out in terms of culture. There has been a steady stream of people leaving the company in the past 3-4 months; probably about 50% involuntary.