I am not remotely interested in such a weapon for self defense. Give me my Glocks or HK USP's.
At any range beyond close, you run the risk of wounding without killing. Although most shootouts are VERY close range, I still would prefer the greater range afforded by a regular round.
Finally, I don't really want to deal with the lawsuit of the wounded criminal. If I am ever faced with shooting, God forbid, I don't want to wound the criminal.