This is probably the most powerful plugin for Google Maps. I tried several of the offered plugins here, but none of them were able to give me the functionalities which I required.
I purchased the pro edition of "wp Google Maps" in order to get access to nearly all functions. I have made a .csv with more than 100 markers and uploaded them into the map.
Well, where is then the missing star?
The plugin is unfortunately not easy to handle. Messages are missing and errors mostly not displayed. You have to figure out most of the advanced stuff by yourself. It took me about 15 hours to get everything handled.
In the end, I am just happy to have found this plugin which has a lot of power inside. If you have the time and the stamina to get everything settled, you will love it.