Hello,
I am sad to hear about your experience. Conures have the reputation of napping, but this is clearly a bit more advanced aggression. Amigo, my pearly conure never bites me anymore, however he does try at times when there are other people present. He is not aggressive, however he is a tad territorial around his cage. One of the problems with hand-raised birds are just the fact that they are not afraid of humans to begin with, and often has somewhat of a 'blind' trust. The sneak attack it very hard to predict and avoid, however I would strongly recommend you to look up Barbara Heidenreich, she runs Good Bird Inc.
Barbara has got a saying, and it goes something like this; If you learn to read your bird, you should never get bitten. If you get bitten, it's your fault. Now that is of course not something you would expect an untrained eye to be able to do, but she has got a lot of videos (DVD's with teasers on youtube) on parrot behaviour. I have all her DVD's and I do recommend her. She is all about positive reinforcement.
My best advice would be to try and control the situation, more so to not "turn your back" on the bird when he is outside of his cage, and remove his element of surprise.
Now taking into account that you said he is more aggressive towards men, this tells me that he might just be a boy, and he may have claimed you as his "partner". Would it be right to assume he is in the one to four year old range? This may just be the hormonal phase of sexual maturity. It can also be in relation to territory, however that is usually more based around the cage area in my experience.
Small birds are harder to avoid when it comes to bites, as they can leap forward in flight. But avoidance is the best medicine to treat aggressive behaviour, and hopefully the bird will start to realise that biting is not an effective behaviour to use.
I would be happy to share some more of my experience with conures if you want, some more details around the attack and the leading up to the attack might help paint a better picture!
Best of luck, I hope you overcome this phase and end up with a bird that you can trust around people. Some birds just simply does not trust people they don't know and may display aggressive behaviour by default, but I believe you can still overcome this. You might not get a bird that trust all people, but if you can prevent the attack, then that's at least something.
