Update:
They are still working on getting iTrader back up (which was that handy-dandy trader feedback system we had going on at DAGG), but in the meantime, the
Trader Feedback Forum is working. There should be one thread for each member wherein you can leave a post regarding feedback after you complete a trade with them. Please DO leave feedback, whether it be positive or negative (as long as you've tried to work things out with them), and please do CHECK feedback before you trade with anyone else as well.
Good luck!
Nikki