Pros
As an employee, you get cheap access to Fidelity's products, such as brokerage account, mutual funds, etc. If the assets are under Fidelity management, you get it cheaper. For example, a person with an HSA account at another firm pays annual fees, because Fidelity runs your HSA, you don't get hit with fees. Also, Fidelity spends a ton of money on technology, so you will have nice desktop hardware and software. The facilities are generally nice and well stocked with coffee and tea.
Cons
As an employee, you are forced to use Fidelity's products, e.g., you can't have a brokerage account anywhere else or a financial advisor if he or she places trades and if you buy other company's mutual funds, you have to report it. The culture is almost like a fuedal manor with a benevolent lord. The employees are expected to show tremendous loyalty to the firm. To hear some talk, there is no other place they could ever work. This used to be okay when Mr. J was more involved and the managment reciprocated some of that loyalty. But it just isn't the case anymore. At any given time you could have your job moved to a cheaper state, India, or just plain eliminated. Sr. managment communication is full of sports metaphores and lofty vision statements, but surprisingly silent about long term plans related to employees such as site closures or changes to business lines. Increasingly we have stealth layoffs. The only way you hear about whole areas being eliminated is if you happen to have a friend that works there. People just disappear off the company directory. At least in 2001 and 2002 they bothered to tell everyone what was going on. Lastly, it has become almost impossible to move internally. They recently added another HR layer between a candidate and a hiring manager, so now if you want to post you have to go through your manager, an "internal staffing rep" who will decide whether you should even be thinking about moving, a staffing rep who will decide if you should be considered for the position, and then finally the hiring manager. Most of the time the hiring manager never even sees your resume. If you do happen to get that far, the hiring manager is prohibited from making an offer until he or she has gotten a reference from your current manager. If you do apply for a position and you aren't being considered, no one ever bothers to tell you.