I am Southern and I suppose that is why--even though I am an adult--I still address people with Miss, Ms., Mrs., or Mr. before their last names (and I use Ms. unless I know for sure that the person uses Miss or Mrs. instead).
As I am in my mid-thirties, unmarried, and a professional, I use Ms. Thetanustew. Miss Thetanustew makes me feel like I am about six and still wearing my hair in pigtails! Mrs. Thetanustew is my mother because that is how she identifies herself. She was quite happy to go from being Miss Notthetanustew to Mrs. Thetanustew.
I am fortunate, though, that because of my job I can have people call me Professor Thetanustew...and in about six weeks, they can call me Dr. Thetanustew! That should solve ANY title problems.
Even with all the overeducation notwithstanding, I'd highly prefer to Ms. over Miss or Mrs. any day. Whether or not a man is married has nothing to do with how one addresses him. Whether I am married or not has nothing to do with how one should address me, either!
I have no idea why I am so dogmatic about this; none of the other women in my family on either side have ever used anything but Miss or Mrs. . . I suppose it's just one more way that I am the oddball in the group!
My two cents. Keep the change!