I ran some experiments and found that pre-generated mapping views can improve start up time for things like the designer (and potentially other services that use the schema discovery model, such as a default DatabaseTableChecker implementation).
In the case of SQL Sever it only saves around half a second in my box, but it could be more significant for other databases.
In the case of SQL Sever it only saves around half a second in my box, but it could be more significant for other databases.