You're a little late asking this since Gox. Most of the people that lost a lot are gone. But due to security issues I lost about 200 BTC.
200 BTC is quite a fair sum. What security issues caused the loss?
Mostly key management, but I'm at a loss for much of it. I brought these issues to the attention of the devs and they added safeguards for future loss prevention. That's why I'm still helping fight FUD and not divested.