I have a website that lists members of an association. They wanted their members to be findable via a map. After trying several other plugins, I found that MapPress Pro did the job.
The free version's good, but I needed more functionality, such as automatically creating maps for 200 postcodes held in a custom field in a specific custom post type. For that you need Pro.
The documentation's pretty good. I did have a few minor stumbles while setting up the map, but within an hour I had fully functioning maps.
I'd like to see an option to regenerate all maps from scratch. At the moment you have to manually edit a post to re-map it, which is time consuming if you have hundreds of posts.