The extension rgsimplegooglemaps has been developed because of the following reasons: Google Maps is often used to display just 1 POI, e.g. for the contact page to show where the website owner is located. Extensions like rggooglemap is far too big for this issue!
With rgsimplegooglemaps this is really easy because you don't need any tt_address record because you select the location directly in the flexforms using the geocoding feature if you want to.
In the frontend you get the Google Maps with an optional direction feature. Additionally the location of the client can be calculated and can be displayed and/or used for the direction feature.
Please take also a look at: