Im having problems with poloniex while trying to withdraw my coins. it is quite slow, but I heard good things about them. You cant completely trust 100% in an online exchange. They aren't regulated by a central agency or anything.
I agree. Poloniex is having many problems in their site frequently. Try some exchanges like bittrex.Don't just settle on two exchanges because there are many sites out there and try doing arbitrage.
Poloniex is experiencing serious problems, we are certainly worried about the security of the money we invest there. We are worried about the cryptocurrency that is still stored in the exchange. I agree that bittrex is the best altrnative, bittrex is still the best besides poloniex.