If you people mine and deposit to poloniex then it makes a lot of difference, trust me, friend of mine when mining to btc-e used to pay only one transaction, when on poloniex then always 2 transactions are paid, you have to decide, its not free. I then sent an email to poloniex and asked about it and they confirmed that 2 transactions are charged. Now if you dont care about being charged more than you should be then send to btc-e, however at btc-e the btc withdraw is very expensive, so in that sense better to deposit at poloniex.
I think stored coin in the exchange is not advisable sometimes the exchange change the wallet adress that you dont know not always but sometimes like that my suggestion is you have to dowload the wallet to your computer and back up it in usb you can always open it anytime you want to use your coins/token about the price that goes up its not good for us even bitcoin now also have a fee if you want to transact your coins its better you transact 1 time with a big amount of money so only 1 time transact only
