I used to trade in IDEX and EtherDelta sometime back and during those times the volumes were low in some of the coins but i still liked trading in those platform until the big news of decentralized EtherDelta got hacked, i was confused on how a decentralized exchange got hacked at that time and then there was IDEX blocking users from NY, if they can do that it is not truly decentralized as they claim to be and then i never visited them after that, right now i am not sure which is a good DEX exchange.