IMO, the South side store is a much better shopping experience and it has air conditioning, which helps keep dry goods fresher.
We shop at the south store as well (were just there today, as a matter of fact!) and often their prices are less for the same item. But the selections in both stores can vary, and sometimes the in-town store has an item the south store does not have (and vice versa). Since we live north of the bridge we often go to the in-town store by default to avoid riding our bikes on all those cobbles!
Emily
AmbergrisCaye.com 
