Pluspunten
It's a widely respected company with a good graduate program, on the job training and (in theory) career improvement. There are free snacks (but not meals, unless you count breakfast at 6AM and dinner after 8PM - I kid you not). The money is good (before tax!) and there are yearly pay reviews which can be generous if you're fortunate enough to have helped the company out in some way (like fix a disastrous outage) or are especially sycophantic.
Minpunten
Bloomberg is a big company organised into product silos and where you land will make all the difference to your experience (hence the polarity of opinion here). You may or may not end up with an idiot for a team leader, you may find yourself working on proprietary systems, completely isolated from industry standards, business practices and protocols, you might be working in a team with no social cohesion whatsoever. And things can change radically overnight. The team whose company you do enjoy might need you to work on another project in another team or the boss with whom you have a good working relationship might suddenly move back to the US and a clueless, dogmatic, despotic, company-man appear in his place. The hours are long and you will find plenty of colleagues, bereft of social lives, who will show you up by arriving early and leaving long after you go home. Although you will be contractually obliged to work 9 hours per day, expect to consistently work at least 10, many work 12 hours or more. You might work there for years and never have anything challenging or important to work on. There is a company policy known as keeping-the-lights-on which translates to if-it-ain't-broke-don't-fix-it meaning the rate of development progress can be slow as molasses. This is especially frustrating and can be soul destroying for the creatively minded. Technologically, Bloomberg is incapacitated by decisions made decades ago and its terror of losing market share is tangible. This manifests as the front-end looking like something from the 1980s but, worse still, developers are forced to use company-specific versions of tools and programming languages, meaning they will not be able to keep up-to-date with modern versions and practices which is poison for career programmers. It lacks effective testing frameworks and the majority of teams are required to develop, test and release everything themselves, at their own peril. Some teams do have dedicated roles for QA and deployment but there's no company-wide policy. Expect to be called regularly at weekends and unceremoniously at 2AM because the network undergoes maintenance every day and anything consuming tick data will set off alarms when it stops arriving. Promotion to positions of authority is patently based on the Peter Principle and micromanagement and an absolutely obsessive focus on negativity are the norm. It's well known that the Team Leaders and managers often form cabals so just one of them not liking you could spell game over for your position at the company. If this happens, get out before they fire you, and they will - you have been warned.