Ventajas
I like my coworkers. Hard working folks that truly know their jobs. Functional management has always supported me pursuing (and paying for) my master's degree and additional training. They really want you to be happy where you are and if not they try their best to move you where you might be. Project managers are less interested in your personal growth, especially if it means edging out an extra buck off you on a contract but I suppose that's why functional management exists to complement them.
Desventajas
Contract work can be difficult. You typically do a lot of flying (but with work from home) if you're not onsite. If you're an onsite analyst you may be asked to relocate and the locations aren't always ideal. Project managers should be more willing to dish out some additional training, especially when I know for a fact they're earning the company two to four times off of me what I earn in a single year.