I'm afraid it all ends up in the same way with altcoin exchanges. I trade also on poloniex, but i'm not in any way confident that
they won't be the next in the line to get "hacked", so better just make your trade and withdraw your coins afterward - don't leave anything on the site.
Well their service is prompt and solid, it doesnt feel as shaddy as Crypsty did, but then again, you could say this of any non legally regulated website and even so, there are plenty of legal ways to get ripped off here so. Use them, but don't keep too much capital on them...