Well as far as reliability of the motor I wouldn't think so. It was put in to purely cancel out vibrations that would transfer into the cabin. As far as longevity of other things such as interior panels and all around quiet I would think it would deteriorate those things faster resulting in more rattles and such developing.
I too have wondered this though. I have never seen one in person and no picture really does it justice so I can't say whether or not it really has any effect in actually balancing and components in the motor. I mean lets put it this way. If the motor and things in it are that unbalanced to begin with then you have a serious problem anyway.