Pros
Besides the great benefits (health care, snacks, dinner), Bloomberg is a good place for you to learn and to work. It provides good internal mobility if you want to move to a different group and location. The open environment provide both an opportunity and distractions. The culture encourages team work, helping the customers. Since there is no title, the management generally is more accessible and it is easier to contact someone outside your team. It does have work from home policy, and the application sometimes depends on your team leader.
Cons
Like many other big companies, there is bureaucracy and internal politics. Sometimes, the accountability can be poor. But since Mike's return, it has changed somewhat to breakdown the silos and to get in touch with the customers more. The technology on the IT side is not the most advanced ones, and there are lots of legacies. But there are lots of smart people and lots of new technologies are being used in various places.