Driveshaft Dampers and purpose?

I've been searching for info on the newer AL drive shafts and their heavy iron harmonic damper ring. Not able to find much info...on how necessary it is
to keep the damper. Anyone have some wisdom on this??? Must keep it? Can throw it out? It resembles having a second flywheel on the tranny tailshaft.
An '80's vette one is quite small, as is the shaft, and Ford Ranger one is huge, as it has a larger drive shaft. Did find one site w/good info on explaining chassis vibration diagnosis:
http://www.quadratec.com/jeep_knowledgebase/article-36.htm

 

Surely there's a wizard in house?

 

you can get rid of it if the shaft is balanced after you take the ring off.

 

It's mostly used with OD trannys. When overdriving the shaft, harmonics are not unusual, depending on how much you are lugging it. The shaft is still well balanced, but the dampner knocks out the buzz. We may not care, but your average new car buyer would drive the service department crazy with "funny noise" complaints if it wasn't there. Comfort option.