i had two plastic crowns less than 5 years ago - they chipped badly less than 2 years later, while i was eating soft food. dentist re-crowned them with good ole metal - he said he stopped using the plastic (swedish i think).
Gold has the best proven track history and has the best chance of long term success. It does, however, has the worse esthetics of the materials available, just as your doctor says.
Thanks for this info. This is good to find out now and I like to hear it from people who have had the experience. The dentist also recommended the gold over porcelain. Porcelain, apparently, does not last as long and have many other small problems compared to the gold. I was told by the dentist that gold crowns are more superior in its strength, give and fitting capabilities or something. It just doesn't look so special, to me. However, I’ll go with gold, now.
http://ada.org/prof/resources/topics/materials/indirect.asp
This is the current ADA information in regards to materials used for crowns and fillings which are made in the lab.