I did a trade on idex today, it went like a breeze and super cheap (only 50 cents gas fee), deposit, withdrawal, trade everything done within 15 minutes. The same thing would take hours on ED and cost many times more.
There are some nasty rumors going around about Etherdelta being sold to some incompetent person, rumors of exit scams, the very suspicious dns hack which happened a while ago. Stay away from there at all costs, people are screaming on reddit about not being able to withdraw their coins. Deposits and withdrawals don't go through even after transactions are completed with 60+ confirmations on the ethereum blockchain.