I was raised Catholic and lived in SLC for a while in my childhood, and there I was exposed to a good deal of mormonism. Our neighbors would regularly come by our house and ask my parents if they could take me to worship with them. I was around six at the time.
The craziest thing I've heard is that Mormons believe they can convert dead people to their religion to retro-actively save their souls. I've heard they perform rituals to convert Jews who died in the Holocaust to Mormonism so they can go to heaven. I honestly don't know if that's true or not.
I dislike both Mormonism's and Western Catholicism's encouragement of breeding. There's no need for this.
In general I have found the level of education and experience amongst children of large families disparately small compared to their counterparts in smaller families.
I find the concept of patriarchies outdated and sexist.
Likewise for the concept of multiple marriage partners for the Men (I have heard that this only applies to a minority of Mormon cults, but nevertheless).
I don't have a separate opinion on the base myths of Mormonism. They're myths. It's surprising that any educated person still puts stock in stories written by men, despite what deity they claim "wrote" it for them...
Alas, that is our temporal payments for ego and fear.
Ego to think you so special as to have a special place in the afterlife.
And fear enough to invent an image of a temporal afterlife instead of facing our true eternal nature as part of the cycle of life (worm food).