I love YoBit, I have made a fair amount in trading there and ive only ever had one problem sending a coin to wallet and it resolved itself within the hour
They have had problems with there free coins not working but it all seems fixed now
I have used the InvestBox for Dogecoin and they paid like they said and i sent to wallet without any problems, i also did the eth and it paid out as well
I Like this site and use it regularly for trading smaller alt coins
Its the perfect site for beginners i think as there is so much to choose from and they have a dodge market which is cool so you can buy huge amounts of coins in trades
Ive never used there support or never needed it
I have accounts on Poloniex, WEX, Bittrex etc. and trade them all and have done so for years.... say what you will about yobit but i have never had a problem i have only made profit