How about the overall width of the mirrors? Overall bike width, and the fragility of the outermost bike parts is important to me.
I leave my side cases off for months at a time, using them only when I need to carry more than will fit in the Top Case, or when I need to cool beer. That way, the outermost parts on my bike are the stock mufflers. When I put the bike away for the night, I back it through a sliding glass patio door with just a couple inches to spare. When I make my weekly run to Seattle, I park the bike in a semi-legal spot under the viaduct, crowded by other bikes. Whenever I squeeze between obstacles, the first thing hit is a heavy hunk of stainless. I like that little dings on the pipes are down near the ground and covered with road grime. Dings on the mirrors would be up where I'd see them.
The FZ1 mirrors look wider, they look like they don't have the stock mirrors' foldaway feature, and they look a little bit fragile. How tough are they?