Some things that I think you could do to make the map more appealing:
1. Add a border. It can be a simple box or an elaborate pattern as in the map from your question-link: a border helps to set you map apart and it can provide some kind of "anchor" for things like the title or the key.
2. Be careful with your text. I am referring mostly to your labels in this case. Deforming labels should be kept simple, if it is necessary at all. Dropshadows only fit within certain styles - not for a map that is kept simple as yours is, in my view. In this map, they also clash with the outer glow effect you applied to the labels. You should also avoid white for this outer glow... it stands out to much.
The hex-map from your link is a good example of simple but effective labeling. It doesn't use unnecessary distortions and manages to make the labels visible without adding to much overblown effects.
In your case, you could try several things.
You could use the outer glow as a mask to erase / blend out the area surrounding the labels.
You could go the way of the linked map: make the labels and the icons different in brightness... either by making the icons or the text a grey tone.
Or you could colour the labels. In my view, a suble red or perhaps green would provide a nice contrast to the rest of the map.
3. Next, you could add some texture to the map. A subtle parchment or paper texture - something with a little structure - can add a lot to the optics. Again, the map you linked to demonstrates it very well.