Horrible.
Almost every freelancer on the site has rating above 4, so the system is suggesting that it's full of professionals while in fact - it's a bunch of third-world country students strangling everyone in their way just to make an extra buck, disregarding quality of work and communication.
Basically this is what happens:
For example, you post a job in here you will immediately get 30 "professional" Indian/Bangladeshian freelancers offering their services of something that doesn't have anything to do with your job posting at all.
Or if you're a freelancer, you get a bottom-feeding client who will expect you to work for 3$/hr with you being available 24/7.
I can't describe how many absurd people I've found here, sending their personal/family photos, demanding for upfront payments while they have no portfolio or proof they've done any work before whatsoever. Half of them BEGGED for "work" and when you give them something, they either do horrible work or just try to scam you.
I even got my server hijacked by a freelancer from oDesk.
Freelancers, stick to "over 20,000$ spent" clients mostly Australia/UK/US. Most of them are companies looking for outsourced work. And stay professional.
Clients, get off this site. You are most likely getting mugged.