I think we may need to divide the discussion here into two different sections:
A. The tactical/practical value of using a suppressor for self-defense (not the tacti-kewl value).
B. The possible repercussions of utilizing a suppressor.
My answers:
A. Yes there is a practical advantage to using a suppressor, in allowing you to not be defeaned by the discharging of a round in a confined area.
B. No way in hell I'm shooting someone with my "Rambo-style weapon of mass death & destruction, designed only to kill" as I'm sure some trial lawyer will put it. I've dealt with trial lawyers and the subject of weapons as it relates to a court case, and believe me if they can twist something to their advantage they will. And given what most people think of NFA type weapons, I'd hate to give them more ammo to come at me with.