madeinlisboa: Photomatix has a Fusion mode besides Tone Mapping. You get a perfectly exposed photo from a set without the unnatural look and light glitches from Tone Mapping.
A software ND filter won't recover lost highlights. It will never work as the real thing.
The "unnatural look" that you refer to is because most people who use HDR software either do not know what they are doing or they actually like that dreadful "chunky" look. Please understand that the goal of HDR photography should be making an impossible image, not an ugly image. As my wife said, "looking at your [my] images is like the computer screen is a window and I'm looking out that window." At that point I knew I had figured it out.