If you saw a really cool price in MtGox, you would hate the five minute delay in every transaction you're proposing. I think the fast processing of transactions is considered a plus+++ for exchanges.
the five min delay would be for the withdraw of BTC, not for the exchange of BTC. Given the amount of attacks going around, and given that it is ultimately their fault having given out our emails, I would have expected something like that.
Also, the BTC withdraw from my account was automated - it took about 10 sec between the moment I entered the password and the moment I was notified of the withdraw. Captcha anyone?
Yes, I was stupid. But this must be the 30th phishing email I receive. And so it happen that I had just submitted my documents for identity verification. Of course, I don't put the blame entirely on MtGox, but I was expecting them to have set up some extra security measure.