I can't believe this thread has got so long!
I think anyone who says we have the choice over title is a bit deluded. It's all very well saying you chose Mrs, but that's the standard title for a married woman so it's not much of a choice, is it? Most of the women I know are married and they're all Mrs. None of them have chosen anything different. I am a teacher and have only come across a couple of teachers who use Ms.
Of course titles have meaning. What would be the point otherwise? You might think of Mrs as being a mature woman, but that's because most older women are married, or have been. Mrs means "wife of".