I only started using Poloniex about a week before the fork, and my experience with them has gone from great to awful. I'm just waiting for my lends to expire before leaving. Only reason I'd go back is if they feature I coin I'm interested that isn't available elsewhere.
I really like Poloniex, It's got the best volume and a neat user inferface compared to others. But honestly if Polo can't be trusted I don't know what other exchange can be :/