I've had nothing but good experiences on Poloniex, and I also realize that no service is perfect so it's not the (now aging) outages that concern me. What concerns me about Poloniex is their total lack of communication around the outages. If they would have simply recognized the outage, communicate status updates, and even go further to provide updates on upgrading their support group... then I'd feel more comfortable keeping my coin there. There's also the fact that after 5-months I've yet to have my account verified; that tells me they either don't care or running on the bare minimum staff.
You may stay forever with an unverified account. I agree the daily withdrawal limit can be a problem, but it isn't if you're a long term investor.
@richardsNY
I don't think about the Bitfinex hack anymore. It happened more than a year ago.