Got linked up with a freelancer and it was going well until I realized there was no way this person could accomplish the task, and then you are just screwed. The freelancer was making 8th grade graphics, literally thought it was a joke when it first was submitted. I would never use this site again because of the process, you should get a trial period to see if the person can actually do what you are looking for.
Do not ever use this site, and if you do then know how much risk you are taking. I'm sure there are good freelancers on there but few and far between, good luck hunting.