Teatpuller, I think you're pretty much bang on: egg taste is pretty much dependent on hen diet. But like Dick said, only a double-blind test would reveal whether or not the Authentic Farm Hen's egg tasted better than (even) the 'organic, free-range' supermarket egg. [I suspect that it would, hands down, but suspicion's not enough...] I've been in the wine biz for a coon's age, and I know for a fact that unless a tasting is double-blind, cues to identity abound, and humans are sensitive enough to pick up the clues, flawlessly.
Hmmm, thinking a bit more about the determinants of taste, I wonder if exercise makes any difference? A genuine farm hen not only eats bugs and stones and other stuff, she runs about hither and yon, which makes a genuine difference in the taste+texture of her flesh. I wonder if it has anything effect on the taste qualities of her eggs? Interesting...
Sooo, you like wine and are looking for something good to read? Maybe *this*
will do the trick!