Pros
Flexible project(s) allocation: you are allowed to work on multiple projects at the same time, you will learn a certain amount of experience in time management and communication skills through handling different projects at the same time. Thus, in short period, your income might dramatically changed, increasing/decreasing due to project income (base salary remains unchanged).
Cons
Technical dept: fast-paced project, client's change request but keep old schedule and deliverables sometime. This lead to 'just make it work, i can go back to do better later' (mostly, there is no going back to pay technical dept because the project was delivered and your contract with client is completed. you have to handover your works then moving on interviewing new project)