They aren't functionally the same because detaching a production database so you can copy the files takes the production database offline.

I use the backup, copy and restore approach when doing this type of thing.  If you use SQL Server logins, you'll probably have a SID mismatch between the users and the logins on the destination server because the start of authority is the instance.  You can use sp_change_users_login to find and fix them.  If the servers are on the same domain, the AD logins should be fine because the start of authority is the domain.