The sad truth is, you aren't going to find any good writers consistently on sites like those.
Here's why: As contractors bid each other down into oblivion, the good writers/designers/coders/etc take one look, shake their head, and go set up shop on their own site.
It is what it is.
A lot of clients have unrealistic expectations about the quality they are going to get for the going rate on these sites.
At one time or another, I've been both a contractor and client on a number of these sites, and I'd rate over all experiance and contractor expertise this way:
1) Elance
2)Odesk
3) Guru
4) Freelancer
Freelancer is the "spammiest" of these sites by far, and the least professional in both presentation and execution.
If you need good writers, your best bet is to go to a brokerage service like TextBroker or InteractMedia. You will pay more, but you will get more consistent quality.
The best possible solution is to seek out a freelancer with his/her own site. They charge the most,but they are usually professionals.
