Your photos suffer from the two characteristics most often seen in images posted by people new to HDR and Photomatix. First, they are highly processed, to the point that they cross the line between photography and photoillustration. This kind of processing results in noise, halos and over-saturated colors. Second, they haven't had the benefit of any post-processing to correct brightness and contrast. HDR images often have a certain ‘look’ to them, but it’s useful to remember that the purpose of HDR is to capture in a single digital image the entire dynamic range of a scene. HDR technique is beneficial because of the limited sensitivity of digital photographic sensors. It works particularly well on scenes with broad shadow areas and on subjects with a lot of edges (architecture, peeling paint, old cars, etc.). As a tool, Photomatix performs HDR processing beautifully, but it's tonemapping controls are assertive. It's very easy to go over-the-top. The farther over-the-top you go, the more post-processing is required to correct the problems introduced by the tonemapping. My recommendation is to go ahead and use Photomatix's “Tone Mapping, Details Enhancer” combo, because it's powerful, but to go easy on the "Strength" slider. Halos between solid objects and the sky are inevitable and get worse the more "Strength" you apply. Use the "Highlights Smoothness" slider to minimize them. Thereafter, you'll need to use Photoshop or some other post-processing software to correct the contrast and to apply some sharpening. I hope that was helpful.