I have heard many good things about the .357 Sig round, and have put some consideration into moving to this caliber (instead of .45ACP) as my ccw round; as I read all the raves and reviews, I noticed that law enforcement units like the round, particularly, due to its high penetration capability (through car doors and such) due to small size and high velocity. In my thinking, for a private citizen's CCW purposes, that sort of penetration really shouldnt be necessary, and might become a liability in the event that you ever have to fire your weapon.
-tjg