Avantages
When the projects get going, they really go. It can be stressful because time management is really awful on projects but at least it's fast paced.
Inconvénients
Often times the resources you need to work on a project have to come from other parts of the company who didn't want to give up that project in the first place. That can lead to people causing your project to intentionally fail for political reasons despite not even knowing you. It's also a shame because you'll never see them face to face or interact with them outside of email or phone calls. The union is a huge burden on someone who wants to get work done efficiently also, they will drag their feet and honestly nothing can be done about it. No one really wants to spend the time training new people coming in so they stick you in a cubicle, give you a thick book, and leave you there like an office plant.