ifsomebody is planning to make some exchanges, I'd like to share my experience..I decided to try BestRate.org as I  had an extra amount of eth, I made an exchange into xem..and it gave me really profiitable rate with no extra fee and bla bla .. just in case, it's an agregator which provides you with the range of the giants of exchanges such as Changelly, ShapeShift, Evercoin, Bittrex, Poloniex and others..that's why you get the highest rate