Being a slug shooter I would consider the .6" differencedrop between the 170gr 30-30, and the 385gr 12ga to be "virtually identical trajectories" for deer hunting performance. (I agree you are correct in the original statement, that the 30-30 is flatter).

More importantly, (at least for my own purposes). I would never sacrifice a 20%+ drop in energyin hopes of gaininga maximum trajectory difference of .6" on deer sized game.

However, I can understand how shooters that are accustomed to shooting at longer distances don't view the comparison in the same light.