PBS Documentary on the Mormons

My ol' Ball of Twine ("Ball and Chain" if 'twere an unhappy marriage) had us watching this documentary over the last couple of nights. And it got me thinking. Now, I'm not doubting my own beliefs or even wanting to call Mormons "Christians" (they have rejected too much of classical Christian teaching for that). But I found it interesting to recall that all the Mormons I've known were really nice people and good neighbors. Then I recalled my Wife's Muslim friends who are more christian than a lot of Christians I know (if you catch my drift). And I started wondering, how much of this goodness and kindness are natural results of following their religion? And how many of these desirable characteristics are the result of the graciousness of God - his willingness to meet us no matter how faulty our matrix of how to understand our experience of Him? How could somebody study the difference between the two factors?

Your input is welcome.