Hi...
Mormonism is not exactly fresh... Bigamy is a major tenet of their
beliefs. Beyond that it is the claim that they are really
Jewish.
The fact that a group is hardworking and family oriented should not
be the only indicator of whether a group is good or not.
The point of the Christian faith (oh, please people who disagree,
don't start another debate here) is to worship God. Only if you are
at peace with their definition of "God" then should you join a
group.
Beyond that, do bear in mind all religious groups are still run by
people, and shortcomings do happen.
Seeing that you are genuinely considering the option of joining a
Mormon church please, at least visit the following link:
http://www.carm.org/mormon.htm. Within this CARM website can also
be found a definite of what is defined as a cult.