So since getting into Crypto around 2 years ago I have used my fair share of exchanges and in that time I have used some great ones and some not so great ones. I have to say that poloniex is by far the most user friendly system to date. The smoothness of transactions from buying/selling and withdrawing/depositing funds was a process I really liked. I have since invited my father and uncle to join the exchange, one has and the other is in the process. I dont keep my funds on exchanges so have no comment about security but from what I hear it is very safe. Plus being taken over by the smart money makes it an even better choice to do business with. I hope to have a long and happy time dealing with you.