Yes .... I have withdrawn, Steem, Steem Dollars and Doge Coins so far. The 1st one took around 10 days - after that they have all gone much quicker. Steem is the fastest and easiest to withdraw directly to Steemit within a day. I think the larger amounts take longer so I try to withdraw the smallest amount possible and also avoid miner fees. Stems the best for that.... Once in Steemit I can send to Bittrex and buy whatever other coin I want.