Given that most psi sleights in EP are fairly weak I think the asyncs are kind of unbalanced. They really seem to be glass characters that are awfully weak for the minor advantages they get. I meran, they're more vulnerable to mental stress damage under normal conditions, can't download into a non biomorph without going crazy, are more vulnerable to exsurgent virus infection, etc, etc, etc. In most cases their sleights they get in return are pretty weak for the boatload of weaknesses they get in return. I can see most of the weaknesses being valid, but would like to suggest one change to msake the asyncs more playable and more attractive: Instead of being more vulnerable to the EV, could they instead be made resistant to it and get a +20 to resisting it due to the fact they've been exposed to a weak strain of it and have developed a resistance? I think that might make them seem less made of glass and more attractive, and is fully justifiable in game terms.
"I learned the hard way that if you take a stand on any issue, no matter how insignificant, people will line up around the block to kick your ass over it." -Jesse "the mind" Ventura.