I agree with ShirleyW.
Firstly it's hard to say one is a bigger con than the other. They are both selling absolute fiction as the secret truths of the universe.
I use the Mormons often as a good reference point for JW's that think the "brotherhood" is the greatest thing since sliced bread. If you have ever been to a middle-size or smaller town in Utah, the Mormons have accomplished exponentially more in the way of building community than the WT ever will. It is like walking around in a modern day "Leave it to Beaver" episode.
Basically, JW's have a conservative group of relatively passive people that are supposed to be living by basic christian standards.
Mormons have that in spades! I would say the Mormons have JW's beat hands down in that department. They might not have the racial diversity, but i think generally speaking the average Mormon is a better and more devout person than the average JW.
Oh and ditto what Terry said above...
-TE