Well in my 'twisted' opinion it is better than being a Catholic which my friends mother raised him as... And his father followed weird 'eastern religions' which probably involved some 'avodah zarah'.... So ending up Mormon is a step up.... Just my opinion...
I don't know what kind of "Eastern religions" he followed but I probably wouldn't agree with those either. Don't you think that it's idolatry to say that you yourself are a god or potential god? That's what Mormonism teaches men. It also teaches that God's origin is not eternal and without a beginning. They think God has an origin when standard Christian belief is that God is eternal (both eternal past and eternal future, as we would understand it though in simple terms, time is obviously more complex than that in reality and doesn't apply to God in the same way it would to us). I can't believe you don't have a problem with Mormon teachings at least as much as you would with regular Christianity.
Catholicism is something I have doctrinal differences with (for example I don't believe in asking dead people to pray with you, no matter how righteous they might have been), but I do consider many devout Catholics to be real Christians even if I have some differences like that with them because they agree with some core doctrines that cults fail to adhere to.
There are those who try to mix it with some other religion (like is common in some areas like the Caribbean) but I would think they are veering off the path and might not really be Catholic or any other type of Christian anymore anyway.