Poloniex is my favourite exchange. I first registered in Poloniex on May/June 2017. I also got registered in scores of exchanges just around that time and after. Uptil now, I have not come across an exchange that is in anyway close to Poloniex. I will come with my points:
1. User Friendly: Poloniex is the most user friendly exchange I've been. Registration is very simple there. And they don't laden their members with unnecessary requirements. They allow their members to go by their choice. Everything in their platform is very transparent and easy to grab
2. Network Stability: It is only in Poloniex that I don't experience what I experience in other exchange platforms. Because of the tortoise network in other exchanges, I now detest having anything to do with centralised exchanges. And it looks like a common ground for all the exchanges. You will almost shed tears trying to type in amount, or waiting for space to pop to input details. The reason for the cracking and hanging is what I don't know. However, Poloniex is absolutely different. Transactions there moves like water, and you will always feel like visiting again and again.
3. Security: Since I entered Poloniex, there has not been any news on Hack. All the other exchanges have had one or two hacking experiences. Poloniex has been very stable, in spite of the fact that it is one of the earliest exchanges.
4. Support: Poloniex is the only exchange that is so lenient to its members in spite of the level they operate. When the issue of KYC first came, other inferior exchanges jumped into it with high and unnecessary level of strictness, I guess it is because they felt that they have arrived. Poloniex employed the best of decorum and consideration. They didn't jump into no KYC no withdrawal and transaction syndrome exhibited by others, knowing fully well that their members came into their platform without a prior knowledge of KYC. Also, they understood that the fraudulent perpetrators will not withdraw anything less than $1000. They allowed their members to trade and withdraw below $1000 for good 6 months without KYC. She is the most disciplined exchange, yet she is very flexible with her members while applying the best of caution.
I read one of the reviews complain about their support, and I asked myself, "Is it the same support I have had dealings with?" Poloniex has one of the best support systems ever. It takes them just few days to rectify your issue, and that you will not see even among exchanges with less number of participants.
Poloniex has the best way of carrying their members along. They cannot do any slightest thing without informing their members via mail.
5. Withdrawal: I assigned this a different section to buttress a very important point. I have never seen any exchange done awesomely well in delisting a coin as Poloniex does. I wish I will be allowed to mention some exchanges by name as I narrate my ordeal in withdrawing my hard earned currencies from them without any success. A lot of exchanges are frustrating, and I have lost so many coin's there. An exchange will inform you that they are delisting. When you want to trade the coin they want to delist, they will tell you that they have closed the market. When you want to withdraw the coin, they will tell you that the coin is not up to the minimum withdrawal. That mears that you have to forfeit the coin. Poloniex will inform you of the coin she wants to delist, and will give you time to trade it. If you did not meet up within the stipulated time for trading it, they will still inform you to withdraw it within a time frame. Whenever it comes to withdrawing a delisted coin, Poloniex will remove every of its laws binding on or related to withdrawal. In this case, no transaction fee or minimum withdrawal saga. You said you don't need a coin, and you still want to have some amount of that coin for your fees. Is that not criminality? Thank God for Poloniex. She gives us an ideal crypto exchange. It's difficult to encounter problem withdrawing your fund in Poloniex, unless you are sending it to another exchange.