What operating system does it ship with?

It is designed to run a general-purpose OS such as TrueNAS, Unraid, Proxmox or Windows rather than a locked NAS system. Plan to install and configure the OS yourself.

Can it run Plex with hardware transcoding?

Yes. The Ryzen HX PRO 370 has integrated graphics that Plex and Jellyfin can use for transcoding, and the CPU has headroom for several streams.

How many drives can it hold?

Five 3.5-inch SATA bays, plus M.2 slots for NVMe cache or fast storage. That is enough for a small RAID array with room for expansion.

Is Gigabit Ethernet fast enough?

For home media streaming and backups it is fine, but large transfers are capped around 110 MB/s. Users moving big files often want 2.5GbE or 10GbE.

Is it good for beginners?

Not really. It rewards people comfortable installing an OS, managing RAID and using the command line. Buyers wanting a plug-and-play NAS should look at Synology or QNAP.