Pros
Great people in lower level positions. Many great analysts, execs and managers which you will get along with on a personal level. You will meet a lot of new people, but it's mostly because the turnover is so high.
Cons
Incompetent Executive Leadership Team who don't care about employees. Senior management pretend to care about employee well being through staff meetings but don't ever engage with lower level staff. Promotions are almost non existent apart from a small pool of staff who continually get promoted because they shout the loudest. Salary increases are laughable and are even worse when you are promoted internally, you'd be better off moving to a different company in that same role. The business also lacks a clear vision as the vision changes on an ongoing basis. Eventually Columbus will be absorbed by Merkle, which hopefully will be to it's benefit.