I like it... I'm pretty new to this, so if this was once a feature that you had to remove, I have nothing to compare it too. Here is my opinion the feature and where to utilize it.
1) I'm with the color-coded dots as apposed to the icons. The only exception IMO would be for new caches and events.
2) I would prefer to have buttons for zoom in/out. This will leave two options for map clicking and make it more user-friendly.
3) Filtering would be great! The easiest way would be to have checkboxes next to your legend. Simply check or uncheck.
This leads into another feature I would LOVE to see...
Home Areas
From "My Cache Page" I would like to have some pre-defined points of interest. i.e. Home, Grandma's House, Mistress’s House. Each area would have a map, with all the local caches and descriptions below.
BTW:
Great job. It is nice to see an attitude toward continuous improvement.