If 10mm ammunition wasn't $1.50 / round (when you can find it loaded to real 10mm levels...not 40SW levels) I wouldn't own a 45Acp. There isn't anything a 45Acp can do that a 10mm cannot do better.
10mm is an ideal round for people who live in rural areas. It is probably less than ideal for urbanites. Over penetration could be an issue in a crowd.