Okay, so in last ~3 weeks, I've come back into crypto, facing some financial difficulties and putting all last financies into old and good btc. I've been using poloniex a lot and that's what I want to share with you. During this month I've been arbitraging and trading a little and got my coins stucked or lost or somewhat for 3 times on polo. The longest one was 4 days and 6 hours, when the system made coin withdrawal but no actual withdrawal happent. I've got my ticket answered only after 4 days. During this I've lost ~5-10% of value in btc of this alt and lost a huge amount of investment/trading oppotinuties I wanted to try. Even though my problem could be solved in 2 minutes with just giving coins back on the account. And after 2 days since resolving the last issue I got into another. Today I saw a 6% gap between trade price on bittrex and polo and wanted to use it. Bought coins, send on actual, working deposit polo wallet and... Nothing. Absolutely nothing happent. So for now it's over -35% of the initial price and will go even more for sure and it's only 13 hours. My ticket won't be solved until 2 of may when it would be delisted so high chance that I will lost everything. It is the most retarded situation - everything is fine in blockexplorer, they received everything, this can be finished in several clicks by polo, but they don't care. Just because of issue on the other side I'm loosing around 0.04 btc minimum.  I know it's not much, but for me it's pretty significant amount and all losses are only because of the technical issues from the exchange side.  
Now I just hate my life and dislike the poloniex for experiencing it. This experience even more devastating than cryptsy's was.
Bittrex is running much more alts markets. But they somehow can deal with them and most problems are solved in several hours. And tickets are answered after 6-12 hours.
But polo while making like 300-400k$ a day now can't hire enough support staff to deal with 600-700 tickets a day and run 20-30 wallets.
You will have to deal with 2-3-4 or even more days to get your tickets finally answered.

So, what I want to say to you - don't trade with alts of high volatility on poloniex - you'll suffer big losses. Avoid depositing not top alts there. They don't care about you. On the my message of like "Thanks for -30% poloniex" in chat after explaining my problem, I've received answer from moderator like "You are welcome." and then was  banned. They are making money and became a little bit lazy.
Thanks for your attention. Avoid dealing with polo in non top 5-10 alts, or you are risking to lose a lot of time and nerves.