SharePoint 2010 Best Practice: Keep Relational Data in a Database or Migrate it into a Custom List

Is it better to keep relational data in a database or migrate it into a custom list? Or do you need a hybrid solution in the form of external lists giving it the UI of SharePoint, but leaving the data in a relational database?

Benefit	Database	SharePoint List/Library	External list
Handles complex data relationships such as triggers, real constraints (not the approximation of that in SharePoint)	+	- Basic support (http://msdn.microsoft.com/en-us/library/ff798514.aspx)	0
Handles large numbers of items	++	+	+
Handles transactions	+	- (but can be implemented to some degree: http://www.loisandclark.eu/Pages/transactions.aspx)	0
Is easy to use	-	+	0
Accommodates workflows	-	+	0 Basic support (http://social.msdn.microsoft.com/Forums/en-US/sharepoint2010general/thread/426a0bd7-e7cf-496c-9303-76b6f8475ed1/)
Includes a standard interface	-	+	+
Can easily add binary data	-	+	0
Handle versions and show/extract history	-	+	-
Modify/customize UI with standard tools (SPD 2010)	-	++	+
Easier playing with files	-	+	0
Can easily reuse columns definitions (incl. inheritance) – Content Types	-	+	+
Easy integration with Office client applications – Excel export and Document information panel, using standard UI	-	0	+
Web Services access	-	+	+
Easy to integrate with legacy apps (assuming not every app knows how to deal with SharePoint)	+	-	+
Architecture that is simple to understand	+	0	-
Supported capacity	++	+	+ (http://sharepointdragons.com/2011/12/05/sharepoint-capacity-planning/)