Pros
Good clients, and great recruiters to team up with. Like most contract recruiting, a good portion of your experience will be down to timing. If you're needed at a time a good, long term project is available, as long as you're reliable and hard working, you'll work the length of the project, and be given other work. However...
Kontras
Same cons as most contract recruiting. Most recruiters realize that as a contractor, you're never guaranteed ongoing work. What might not be though of - once you're on a project, you're not typically free to just switch to another one if you start to experience burnout doing the same thing for an extended period of time. This can put you in a situation where you're trying to do your best, but if you ask to be moved - there may or may not be other projects. So most recruiters just keep trying to push through project burnout. I would advise anyone considering moving from a perm recruiting role to contract work to make sure they do their utmost to always be ready to be out of work for at least two months, just in case.