I have had a few transactions with Yobit and they were successful. This is the first time I am having a problem. So based on my previous experience I though the exchange was ok. Unfortunately the ETH smart contracts issue appeared. I had bought ETH before on coinbase and transferred to Yobit without a problem. It seems bitstamp is the cause of all this crap, they simply started sending ETH as smart contracts and everything fell apart. Of course the support at Yobit definitely needs some work.