7 The exchange that you mentioned in the article deserves to be said to be the best, but I myself only use two exchanges between the ones you mentioned namely:
 
Binance
IMO, this Binance Exchange is the best, its various features impressed me, both in terms of appearance, futures trading, margin trading, large trading volume and of course a large community.

Poloniex
This Poloniex exchange still makes me feel at home trading, which I like the most in trading margin because I think there is simpler.  Because it was the exchange that made me the first time to trade margin.

And the rest of the other five exchanges are only made in reserve if I get a coin that can be arbitrated to another exchange.

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In connection with my country there is also an exchange called Indodax, of course I did not go through it for my exchange list.

Indodax
Indodax exchange, IMO, the price of BTC or Altcoin is sometimes slow up and down.  in the sense that the price of Crypto is cheaper or more expensive than other large exchanges, so that makes me buy and sell it at large exchanges like Binance and Poloniex.