you should see what the reason of the hack was, was it really a hack or were they scamming. and did they come back from the hack or did they disappear. for example Cryptsy was hacked (claimed it was a hack) but they disappeared. bitfinex was hacked but they are still active and i think they are paying their customers back.
and remember hacks happen everywhere. Yahoo was hacked and they found out a couple of months ago sending everyone Email that "we leaked all your personal information! change your password now!".
Fair enough, bitfinex is also on my radar so definitely want to know if they paid back to the user over time.
And why bittrex?