Panic,
I don't know what your problem is with Chev's description of the device but they have been making a great product for a long time and they know what they are doing. The harmonic balance is there to dampen the severity of torsional vibrations and it makes a huge difference.
As far as the rant about hammering on the front of the crank, that is the way GM instructed to perform the task in the manual. I have not heard of a case where the thrust bearing had to be replaced because of damage caused by this procedure.
