Some of the claims of these sites are sensationalized, but they get the basic beliefs right.
Having been both a Mormon and then a Christian, I can tell you that there are vast differences. The most glaring are:
1) The personification of God and the belief that men may progress to become gods.
2) Exaltation is earned through performing specific ordinances and entering into covenants.
3) There is a “Prophet” on earth who is a spokesman for God in all things both spiritual and temporal. (Which makes the Prophet completely different than the Pope)
What about the outer space thing and the planet Koa?
The stuff about “satan is a spirit brother of Jesus” is also a problem...