The main thing that I think about is that it has to look good on any type of map. Will it look good on a black and white map as well as a color one? Will it fit on a realistic map and a stylized map? You may have to work up a few different versions of any sort of logo - one for color maps and one for B&W maps. But in an effort to be more concise - keep it simple and stay with basic shapes and lines. Yours looks good n all but you'll need a line drawing version for B&W maps.