I personally think that modern psychology has gotten out of hand with all of the labels and criteria for diagnosing certain mental illnesses; I believe things are best kept simple first and only expanded upon when necessary.

With that being said, I believe that out of all of the traits listed as criteria for being diagnosed as a sociopath/ASPD, there is one trait that I think is more important than the rest of them combined: does the person feel guilt? If somebody is incapable of feeling guilt, I think that they could be considered a sociopath regardless of how many other traits of sociopathy they possess.

Then again, I'm no expert; I'm merely somebody who reads a lot.