Pros
They give you the chance to propose changes to improve the processes . The supervision during the job time is weak and you will be free to work without much pressure.
Cons
The Z development was tedious because they involved many manual tasks outside SAP: There is no a comfortable physical location within the office for freelance consultants. The non-corporate email accounts, the shared folders, the USB ports are locked and the security policies are extremely tough that make it difficult to share knowledge.You will not be able to take the documents you produced with you at the end of the project. Too much security to enter the building in Lima Peru, if you arrive 5 mins before your daily start time, you may spend 30 mins in the line before entering.