For true aficionados of landscape photography here is a comparison test using my gradual ND filter holder for Olympus 12mm lens (http://forum.dji.com/thread-86513-1-1.html).
The effect is very subtle since grad filter I'm using here is of 3 stops density only, but the image is clearly better defined in terms of dynamics overall.
First image was taken with no filter, second with gradual filter, finally 3rd image with pola filter stacked behind ND grad for even more dramatic effect.
Effect from grad ND filter is excellent! The one with both grad ND filter & polar filter is a little bit too contrast IMHO.
Agree, pola filters are good for water, but blue sky looks unreal. I'm expecting a lot of good things from my ND grad setup this summer, particularly when shooting landscapes under cloudy skies. Recently I'm building complex motorized DSLR camera slider to explore yet another new-2-me territory of timelapse photography ...