Make use of ALL SharePoint list features
Think about native SharePoint lists as some kind of cache for your external data. It's automatically up-to-date and has all list features available, such as views, sorting, grouping, filters, calculated fields, versioning, search, lookups, metadata, mobile and offline access, Office integration (like Outlook, Access or Excel connectivity), forms, notifications, workflows. You can use all types of lists, for example a contact list for external address data, calendar events, tasks, or custom lists. 3rd party tools will definitely work with Layer2 - as the data is in native SharePoint lists.