Whatever the merits of how people make decisions, this is the market. I've found the most effective way to deal with it is to aim for a very simple base design

Whatever the merits of how people make decisions, this is the market. I've found the most effective way to deal with it is to aim for a very simple base design, and add design elements iteratively rather than attempting to build a complex design and forcing it into place. A few highly polished and professional graphics make a site seem polished, and are easier to get working across multiple browsers.