I've been around and ridden plenty of mares in my day. They're as individual as people, so some have been moody, bitchy, and some have been very tractable and sweet as pie.
I still prefer geldings, because they're less complicated and are food motivated. That works very
well when you have to medicate or supplement them. Mares will sniff it, give you a dirty look, and walk away from the 'poisoned' feed.
I prefer uncomplicated horses, although my gelding Conny was more mareish than some mares. He was a true diva his entire life, and could give the witchiest mare a run for her money.
When he died, I remember one of the last things I told him was, "Now, don't go biting Jesus when you meet Him. I know you'll probably be pissed off, but please don't do that."