my dad currently has a mare, whom is head shy and does have alot of issues, not on her mareish day's
She has no respect for alot of people, and wasnt in my opinion broke properly, i honestly dont like her *Pepper* ( we will be re-training her, she is only 3, 'broken in' at 2
But i have gotten myself a project mare, so i hope that will go well.
I have had a mare before as a lesson horse, who we had our days lol! but i absolutely loved her.
I think it really does depend on their personal personality.