My own instinct, at the present time, is not to trust the exchanges, as much as I respect their ability to carve out a profitable niche. Their operators behave as though they have something to hide, and I, for one, like my business conducted with handshakes and eye contact, not with vague technicalities and opaque operating procedures. MtG:Ox operates the way I would expect some government thrall bank would, not as a bank should run, straightforward and with open books. I mine my own Bitcoins, so I needn't fetter about with these exchanges, but if you cannot do so, yet, I would advise you to find a local bitcoiner with an excess of coin and a deficit of sense (for who, in these times, would sell their coin?) and exchange to Bitcoin in person, with a smile, a handshake, and integrity. That's proper business, I say.