I plan to purchase an Aurender music server. Do I need to use AMM?

You do NOT need to use AMM if you are only using your Aurende's internal/local storage. Aurender scans its own built-in storage automatically. After you finish copying your music files to the Aurender's internal storage, the system software will automatically process the metadata* (cover art, file names, etc.) and present it on the iPad App after the process finishes.
It can take a minute or an hour, depending on how much content you copied, and how much content is already stored on the Aurender.

​So, AMM is ONLY needed when your files are stored on a NAS or external hard drive.

*Note that the files must be properly tagged with metadata in order to appear correctly on the Conductor App.