Iwriter was not all that bad at first but over time they have gotten worse and worse. Now most of the clients who come are just coming because they want really cheap content and yet they seem to want top quality for the skimpy bit of money they pay. All you have to do is look at clients Approval/Rejection rate. Many of them have for example 200 approved and 1000 rejected. Of course this is just an example but if you do the math that means they approve only 1 out of 5 articles. And instead of asking you to revise it they reject it and submit a bad rating on you. And I wouldn't be surprised if some of them are stealing the articles as well.
The reason I say that Iwriter is Horrible is the fact that you get so many articles rejected that you spent your valuable time to write (and for Pennies on the Dollar) and they just reject it.
Many of the clients either don't know what they want and so they don't post clear instructions to what they want which makes it difficult for you to write what they want or they MIGHT be stealing the content.
(Tip from my Mom. If you do write and it gets rejected, turn around and immediately post it on Ezine Articles or another place like
Bubblews so that it is not totally wasted and then if they post it on their site they will be plagiarizing and you can report them.)