Is it better to use the ASPNETDB.mdf or add the tables and other db objects to the project's db?

I was weighing the advantages of using a the ASPNETDB.mdf file in a project's app_data folder vs using the ASPNET_regsql.exe tool to add the db objects to the main db used for a project.  
The advantages of the ASPNET_regsql.exe tool that I have been able to some up with are: easier deployment, one less db and connection string to deal with.  
Are there any other pros/cons to choosing one of the methods over the other?  Is there a preferred way or is one more commonly done than the other?  Is it just personal preference?
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