well, they do have the bad service but the volume is still very high. I think that all those volumes are fake and it can not prove anything. Poloniex is following mt.gox path. Save your money while you still can
I don't think that poloniex will become the new mt. gox. They have been in business for way too long for such a thing to happen. And based on what do you think the volume on Poloniex is fake?
Regardless, you should never keep your full portfolio on an exchange just for security measures.