Pros
The FSD training class will teach you what you need to know about Bloomberg's proprietary technologies. Good opportunity for somebody straight out of uni, who knows C++ to a reasonable but not expert level. For those with a few years experience, getting the same pay and going through the same class is less appealing. Bloomberg's RAPID enviroment and BAS framework are easy to use and quick to develop new features on. Bloomberg work you hard but the satisfaction you get from getting a lot of work done can be addictive. Free snacks and drinks in the pantry is also a plus. Lavish summer parties. Nice new "lunch room".
Cons
Bloomberg are focused on being first to market with new features which means pressure and deadlines and a big tradeoff against writing good quality code. Business guys can be aggressive and look through you, and not enough time is given to planning or design. Compile and linking against all of Bloomberg's dependent libraries takes ages and sometimes fails. The architecture is somewhat dated due to this, plus the presence of legacy fortran code. Outages affecting development occur too frequently. You can befriend training colleagues but most people keep themselves to themselves. The initial training class requires a lot of work and staying late and has an 80% pass mark. Working hours 8am to 6pm or 9pm to 7pm.