Topic: Mongo or Postgres for my new app


I'm about to create a new application with the following features:

- community page (users able to login through devise etc)
- users can add waypoints and shapes (google maps)
- users are able to search for points around them (nearest within 50km, etc)

As Mongodb is quite popular recently, I wondered if I should give it a try
It looks quite good and also supports geo features, so I thought I could give it a try.

On the other hand, there also does not speak anything against activerecord and postgres.
Thats why I would like to get some input from anyone having a little bit more experience with it than I do...

Thanks a lot!