Would like to get comments from experts on which exchange is better to trade from Bittrex, Binance,Etherdelta, Polonix ?
it depends on your country and if you are willing to send your personal information for these sites
there is no perfect exchange at the moment , but if you are in US or Europe and ok with verifying your account then poloniex may be a good shot even their support really sucks these days
just keep it in your mind there is no perfect exchange and you will face problems sometimes dealing with them , unless we start seeing more decentralized exchanges