Attach/detach vs. backup/restore
Backup/restore should normally be your method of choice. It will be quicker in most situations.

You can use it consistently, also for production to test too.

See this related question as well, where the backup/restore vs detach/attach is mentioned:

SQL Server Migration restore backup vs copy data and log files

Make sure you add the WITH COPY_ONLY option to the backup so it does not break the existing maintenance plan backup chain.