Think I can spot some shadow on peak top, thought "this is grad filter" even before reading your spec.
I had noticed that too and with the software that I use to post-process it's not the best to get it right. Photoshop is beyond me; too damn expensive. Lee filters, which I use, are not really that color neutral which is a pain trying to correct. I was thinking about Breakthrough ND glass filters which are color neutral. Exposure bracketing works when there is no movement of trees and bushes and like yourself I sometimes find it hard to process at least using Photomatix. I tried another software once (free trial) and it worked better. Such are the challenges of photography. I wonder how pros do it. I think they expose one shot for the sky and the other for the land and blend in Photoshop.