I've been with Joomla for more than 5 years and I think this is definitely a great map extension.
Works great, doesn't break, no errors, setup in a few minutes, intuitive (no manual required), no need for support.
Free google maps
Can have multiple maps
Can make multiple map markers on the same map
Can include markers description
Can include KML
How to pages on the site
You have to install plugin separately and plug in is not on the same page as component.
It would be nice to include CSS styles for marker's pop-up.
Component description not up to date (does not mention Joomla versions upon 1.5).
No screenshots of extension on The Joomla! Extensions Directory nor on the site description.
Does not work inside of table or div when, eg. I want to put it right from contact form module on the same page.