Both will transfer the database users. They're stored in the database, hence they move with the database.
Neither will transfer the login information. That you'll have to script out, preferably with the SID (check Books Online for details) and create on the other server.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability